EXHIBIT 10.73

                                                                [EXECUTION COPY]





                                  $100,000,000


                           REVOLVING CREDIT AGREEMENT


                                   dated as of


                                 March 31, 1998



                                      among


                         AMSC Acquisition Company, Inc.,


                     American Mobile Satellite Corporation,


                            The Banks Listed Herein,


                   Morgan Guaranty Trust Company of New York,
                             as Documentation Agent,


                                       and


                         Toronto Dominion (Texas), Inc.,
                             as Administrative Agent








                                                                         PAGE

                                TABLE OF CONTENTS

                             ----------------------

                                                                         PAGE

                                    ARTICLE 1
                                   DEFINITIONS

SECTION 1.01.  Definitions..................................................1
SECTION 1.02.  Accounting Terms and Determinations.........................21

                                    ARTICLE 2
                                   THE CREDITS

SECTION 2.01.  Commitments to Lend.........................................21
SECTION 2.02.  Method of Borrowing.........................................21
SECTION 2.03.  Notes.......................................................23
SECTION 2.04.  Maturity of Loans...........................................24
SECTION 2.05.  Interest Rates..............................................24
SECTION 2.06.  Commitment Fees.............................................25
SECTION 2.07.  Optional Termination or Reduction of Commitments............26
SECTION 2.08.  Method of Electing Interest Rates...........................26
SECTION 2.09.  Mandatory Termination and Reduction of Commitments..........28
SECTION 2.10.  Optional Prepayments........................................29
SECTION 2.11.  General Provisions as to Payments...........................29
SECTION 2.12.  Funding Losses..............................................30
SECTION 2.13.  Computation of Interest and Fees............................30

                                    ARTICLE 3
                                   CONDITIONS

SECTION 3.01.  Closing.....................................................31
SECTION 3.02.  Borrowings..................................................33

                                    ARTICLE 4
                         REPRESENTATIONS AND WARRANTIES

SECTION 4.01.  Corporate Existence and Power...............................34
SECTION 4.02.  Corporate Authorization; No Contravention...................34
SECTION 4.03.  Government Approvals........................................34
SECTION 4.04.  Binding Effect..............................................35
SECTION 4.05.  Litigation..................................................35
SECTION 4.06.  No Default..................................................35
SECTION 4.07.  ERISA Compliance............................................36



                                        i




                                                                         PAGE

SECTION 4.08.  Title to Property...........................................37
SECTION 4.09.  Taxes.......................................................37
SECTION 4.10.  Financial Condition.........................................37
SECTION 4.11.  Environmental Matters.......................................38
SECTION 4.12.  Regulated Entities..........................................38
SECTION 4.13.  Subsidiaries................................................39
SECTION 4.14.  Insurance...................................................39
SECTION 4.15.  Business....................................................39
SECTION 4.16.  Disclosure..................................................39

                                    ARTICLE 5
                                    COVENANTS

SECTION 5.01.  Information.................................................40
SECTION 5.02.  Certificates; Other Information.............................40
SECTION 5.03.  Notices.....................................................41
SECTION 5.04.  Conduct of Business; Preservation of Corporate Existence....43
SECTION 5.05.  Maintenance of Property.....................................43
SECTION 5.06.  Maintenance of Insurance....................................43
SECTION 5.07.  Payment of Obligations......................................47
SECTION 5.08.  Compliance with Laws........................................47
SECTION 5.09.  Inspection of Property and Books and Records................47
SECTION 5.10.  Environmental Laws..........................................48
SECTION 5.11.  Use of Proceeds.............................................48
SECTION 5.12.  No Subsidiaries.............................................48
SECTION 5.13.  Government Approvals........................................48
SECTION 5.14.  Further Assurances..........................................48
SECTION 5.15.  Limitation on Liens.........................................49
SECTION 5.16.  Disposition of Assets, Consolidations and Mergers...........50
SECTION 5.17.  Employee Contracts and Arrangements.........................52
SECTION 5.18.  Investments.................................................52
SECTION 5.19.  Transactions with Affiliates................................52
SECTION 5.20.  Compliance with ERISA.......................................52
SECTION 5.21.  Restricted Payments.........................................53
SECTION 5.22.  Accounting Changes..........................................53
SECTION 5.23.  Limitation on Indebtedness..................................53




                                       ii




                                                                         PAGE

                                    ARTICLE 6
                                    DEFAULTS

SECTION 6.01.  Events of Default...........................................54
SECTION 6.02.  Notice of Default...........................................59

                                    ARTICLE 7
                                   THE AGENTS

SECTION 7.01.  Appointment and Authorization...............................59
SECTION 7.02.  Agents and Affiliates.......................................59
SECTION 7.03.  Action by Agents............................................59
SECTION 7.04.  Consultation with Experts...................................59
SECTION 7.05.  Liability of Agents.........................................59
SECTION 7.06.  Indemnification.............................................60
SECTION 7.07.  Credit Decision.............................................60
SECTION 7.08.  Successor Agent.............................................60
SECTION 7.09.  Agents' Fees................................................61

                                    ARTICLE 8
                             CHANGE IN CIRCUMSTANCES

SECTION 8.01.  Basis for Determining Interest Rate Inadequate or Unfair....61
SECTION 8.02.  Illegality..................................................61
SECTION 8.03.  Increased Cost and Reduced Return...........................62
SECTION 8.04.  Taxes.......................................................64
SECTION 8.05.  Base Rate Loans Substituted for Affected Euro-Dollar
               Loans.......................................................65

                                    ARTICLE 9
                                 PARENT GUARANTY

SECTION 9.01.  The Parent Guaranty.........................................66
SECTION 9.02.  Guaranty Unconditional......................................66
SECTION 9.03.  Discharge Only Upon Payment in Full; Restatement in
               Certain Circumstances.......................................67
SECTION 9.04.  Waiver by the Parent Guarantor..............................67
SECTION 9.05.  Subrogation.................................................68
SECTION 9.06.  Stay of Acceleration........................................68
SECTION 9.07.  Subordination...............................................68




                                       iii




                                                                          PAGE

                                   ARTICLE 10
                                  MISCELLANEOUS

SECTION 10.01.  Notices.....................................................70
SECTION 10.02.  No Waivers..................................................70
SECTION 10.03.  Expenses; Indemnification...................................71
SECTION 10.04.  Sharing of Set-offs.........................................71
SECTION 10.05.  Amendments and Waivers......................................72
SECTION 10.06.  Successors and Assigns......................................72
SECTION 10.07.  Collateral..................................................74
SECTION 10.08.  Governing Law; Submission to Jurisdiction...................74
SECTION 10.09.  Counterparts; Integration; Effectiveness....................74
SECTION 10.10.  Waiver of Jury Trial........................................75
SECTION 10.11.  Confidentiality.............................................75

COMMITMENT SCHEDULE
PRICING SCHEDULE
DISCLOSURE SCHEDULE
EXHIBIT A - Note
EXHIBIT B - Opinion of Counsel for the Parent Guarantor and the Borrower 
EXHIBIT C - Opinion  of  Special  Counsel  for the  Agents  
EXHIBIT D -  Assignment  and Assumption Agreement 
EXHIBIT E - Subsidiary Guaranty





                                       iv





                           REVOLVING CREDIT AGREEMENT


     AGREEMENT dated as of March 31, 1998 among AMSC ACQUISITION COMPANY,  INC.,
AMERICAN MOBILE SATELLITE  CORPORATION,  the BANKS listed on the signature pages
hereof,  MORGAN GUARANTY TRUST COMPANY OF NEW YORK, as Documentation  Agent, and
TORONTO DOMINION (TEXAS), INC., as Administrative Agent.

     The parties hereto agree as follows:



                                    ARTICLE 1
                                   DEFINITIONS

     SECTION 1.01.  Definitions.  The following terms, as used herein,  have the
following meanings:

     "ACTEL" means African Continental Telecommunications Ltd.

     "ACTEL  Agreement"  means the agreement among AMSC Subsidiary  Corporation,
the Parent Guarantor and ACTEL, dated as of December 2, 1997,  pursuant to which
the  Borrower  will lease its  MSAT-2  satellite  to ACTEL,  as in effect on the
Effective Date.

     "Acquisition"  means the acquisition by the Borrower of 100% of the capital
stock  or other  equity  interests  of  ARDIS  pursuant  to the  ARDIS  Purchase
Agreement.

     "Adjusted  London  Interbank  Offered  Rate" has the  meaning  set forth in
Section 2.05(b).

     "Administrative Agent" means Toronto Dominion (Texas), Inc. in its capacity
as  administrative  agent for the Banks  hereunder,  and its  successors in such
capacity.

     "Administrative  Questionnaire"  means,  with  respect  to  each  Bank,  an
administrative  questionnaire in the form prepared by the  Administrative  Agent
and submitted to the  Administrative  Agent (with a copy to the  Borrower)  duly
completed by such Bank.



                                        1





     "Affiliate"  means, as to any Person,  any other Person which,  directly or
indirectly, is in control of, is controlled by, or is under common control with,
such  Person.  A  Person  shall be  deemed  to  control  another  Person  if the
controlling  Person  possesses,  directly or indirectly,  the power to direct or
cause the direction of the management and policies of the other Person,  whether
through the ownership of voting  securities,  by contract or otherwise.  Without
limitation,  any director,  executive officer or beneficial owner of 25% or more
of the equity of a Person shall,  for the purposes of this Agreement,  be deemed
to control the other Person,  and each Shareholder  Guarantor shall be deemed to
be an Affiliate.

     "Agents" means the  Administrative  Agent and the Documentation  Agent, and
"Agent" means either of the foregoing.

     "AMRC Holdings" means AMRC Holdings, Inc., a Delaware corporation,  and its
successors.

     "Applicable  Lending  Office"  means,  with respect to any Bank, (i) in the
case of its Base Rate Loans, its Domestic Lending Office and (ii) in the case of
its Euro-Dollar Loans, its Euro-Dollar Lending Office.

     "ARDIS" means, collectively,  Motorola ARDIS Acquisition,  Inc., a Delaware
corporation,  Motorola  ARDIS,  Inc.,  a  Delaware  corporation,  ARDIS  Holding
Company, a New York general partnership, Radio Data Network Holding Corporation,
a Delaware corporation, and ARDIS Company, a New York general partnership.

     "ARDIS Purchase  Agreement" means the Stock Purchase  Agreement dated as of
December  31, 1997 among the  Borrower,  the Parent  Guarantor,  Motorola  Inc.,
Motorola ARDIS Acquisition, Inc. and Motorola ARDIS, Inc.

     "Asset Sale" means any sale, lease or other disposition (including any such
transaction  effected by way of merger or consolidation  and the Satellite Lease
Arrangements)  by the Parent  Guarantor or any of its Subsidiaries of any asset,
including  without  limitation any  sale-leaseback  transaction,  whether or not
involving a capital lease,  but excluding (i)  dispositions of inventory,  cash,
cash equivalents and other cash management  investments and obsolete,  unused or
unnecessary  equipment and undeveloped real estate, in each case in the ordinary
course of business and (ii) dispositions to the Parent Guarantor or a Subsidiary
of the Parent Guarantor.

     "Assignee" has the meaning set forth in Section 10.06(c).



                                        2





     "Availability  Period" means the period from and including the Closing Date
to but not including the Termination Date.

     "Bank" means each bank listed on the signature pages hereof,  each Assignee
which  becomes  a Bank  pursuant  to  Section  10.06(c),  and  their  respective
successors.

     "Baron  Capital"  means Baron Capital  Partners,  L.P., a Delaware  limited
partnership.

     "Baron Capital  Guaranty"  means the Guaranty,  dated as of March 31, 1998,
made by Baron  Capital to the  Administrative  Agent for its own benefit and the
benefit of the Banks, as the same may be amended from time to time.

     "Baron Capital Letter of Credit" means the Letter of Credit dated March 31,
1998  issued by The Bank of New York for the  account of Baron  Capital  for the
benefit of the Administrative Agent on behalf of the Banks.

     "Base Rate" means, for any day, a rate per annum equal to the higher of (i)
the Prime Rate for such day and (ii) the sum of 5/8 of 1% plus the Federal Funds
Rate for such day.

     "Base Rate Loan"  means (i) a Loan which  bears  interest  at the Base Rate
pursuant  to the  applicable  Notice of  Borrowing  or Notice of  Interest  Rate
Election or the  provisions  of Article 8 or (ii) an overdue  amount which was a
Base Rate Loan immediately before it became overdue.

     "Borrower" means AMSC Acquisition  Company,  Inc., a Delaware  corporation,
and its successors.

     "Borrowing"  means a borrowing  hereunder  consisting  of Loans made to the
Borrower  on the same day  pursuant  to Article 2, all of which Loans are of the
same Type  (subject  to Article 8) and,  except in the case of Base Rate  Loans,
have the same initial Interest Period. A Borrowing is a "Base Rate Borrowing" if
such Loans are Base Rate Loans or a  "Euro-Dollar  Borrowing"  if such Loans are
Euro-Dollar Loans.

     "Capital  Lease  Obligations"  means all monetary  obligations  of a Person
under any leasing or similar  arrangement  which,  in  accordance  with GAAP, is
classified as a capital lease.

     "Cash Equivalents" means:



                                        3





     (a) securities  issued or fully  guaranteed or insured by the United States
Government or any agency  thereof and backed by the full faith and credit of the
United States having  maturities of not more than twelve months from the date of
acquisition;

     (b) certificates of deposit,  time deposits,  Eurodollar time deposits,  or
bankers'  acceptances  having in each case a tenor of not more than six  months,
issued by any Bank, or by any U.S.  commercial bank having combined  capital and
surplus of not less than $500,000,000 whose short term securities are rated both
A-1 or higher by  Standard  & Poor's  Corporation  and P-1 or higher by  Moody's
Investors Services, Inc.;

     (c)  commercial  paper of an issuer rated either at least A-1 by Standard &
Poor's  Ratings  Group, a division of  McGraw-Hill,  Inc.  and/or P-1 by Moody's
Investors  Service Inc. and in either case having a tenor of not more than three
months;

     (d) repurchase  agreements  fully  collateralized  by securities  issued by
United States Government agencies; and

     (e) money market  mutual  funds  invested in the  instruments  permitted by
clauses (a), (b), (c) and (d) above.

     "CERCLA" has the meaning specified in the definition "Environmental Laws".

     "Change In  Control"  means (i) any person or group of persons  (within the
meaning of Section 13 or 14 of the Securities  Exchange Act of 1934, as amended)
(other than any Shareholder Guarantor, AT&T Wireless Services, Inc. or Motorola,
Inc.)  shall  have  beneficial  ownership  (within  the  meaning  of Rule  13d-3
promulgated by the Securities  and Exchange  Commission  under said Act) of more
than 25% of the outstanding  capital stock of the Parent Guarantor,  (ii) Hughes
shall have  beneficial  ownership  of less than 25% of the  outstanding  capital
stock of the Parent  Guarantor,  except  solely as a result of the  issuance  of
additional  capital stock by the Parent  Guarantor to Persons other than Hughes,
in which case a Change of Control under this clause (iii) shall not occur unless
Hughes  shall  have  beneficial  ownership  of less than 10% of the  outstanding
capital stock of the Parent Guarantor,  (iv) during any period of 24 consecutive
calendar  months,  individuals who were directors of the Parent Guarantor on the
first day of such period  shall cease to  constitute  a majority of the board of
directors of the Parent  Guarantor  (ignoring for this purpose  replacements  of
stockholder-designated  directors by successor directors  designated by the same



                                        4





stockholder or group of stockholders),  or (iv) the Parent Guarantor shall cease
to own all of the outstanding capital stock of the Borrower.

     "Closing  Date" means the date on or after the Effective  Date on which the
Documentation  Agent shall have received the documents  specified in or pursuant
to Section 3.01(a).

     "Code"  means  the  Internal  Revenue  Code of  1986,  as  amended,  or any
successor statute.

     "Commitment"  means any  Tranche A  Commitment,  Tranche  B  Commitment  or
Tranche C Commitment,  and "Commitments"  means any or all of the foregoing,  as
the context may require.

     "Commitment Fee Percentage" means a rate per annum determined in accordance
with the Pricing Schedule.

     "Commitment  Reduction Date" means each March 31, June 30, September 30 and
December 31 from and including  June 30, 2002 to but  excluding the  Termination
Date.

     "Commitment Schedule" means the Commitment Schedule attached hereto.

     "Communications  Asset" means a terrestrial or satellite antenna,  licensed
site, base station,  communications ground segment, network operations center or
other telecommunications facility (other than a satellite).

     "Consolidated Capital Expenditures" means, for any period, the additions to
property, plant and equipment of the Borrower and its Consolidated  Subsidiaries
for such period, as determined in accordance with GAAP.

     "Consolidated  Current Assets" means at any date the  consolidated  current
assets of the Borrower and its Consolidated  Subsidiaries  determined as of such
date.

     "Consolidated  Current  Liabilities" means at any date (i) the consolidated
current liabilities of the Borrower and its Consolidated  Subsidiaries plus (ii)
the  Contingent  Obligations of the Borrower and its  Consolidated  Subsidiaries
with respect to the current  liabilities  of any Person (other than the Borrower
and its Consolidated Subsidiaries), all determined as of such date.



                                        5





     "Consolidated  Net  Working  Investment"  means  at any  date  Consolidated
Current  Assets  (exclusive  of cash and cash  equivalents)  minus  Consolidated
Current Liabilities (exclusive of Indebtedness).

     "Consolidated Subsidiary" means at any date and with respect to any Person,
any Subsidiary or other entity the accounts of which would be consolidated  with
those of such Person in its consolidated financial statements if such statements
were prepared as of such date.

     "Contingent  Obligation"  means,  as applied to any  Person,  any direct or
indirect  liability  of that Person  with  respect to any  Indebtedness,  lease,
dividend,  letter of credit or other  obligation (the "primary  obligations") of
another  Person (the "primary  obligor"),  including,  without  limitation,  any
obligation  of  that  Person,  whether  or  not  contingent,  (a)  to  purchase,
repurchase  or  otherwise  acquire  such  primary  obligations  or any  property
constituting direct or indirect security therefor,  or (b) to advance or provide
funds (i) for the payment or discharge of any such primary  obligation,  or (ii)
to  maintain  working  capital  or equity  capital  of the  primary  obligor  or
otherwise to maintain the net worth or solvency or any balance sheet item, level
of income or  financial  condition  of the primary  obligor,  or (c) to purchase
property, securities or services primarily for the purpose of assuring the owner
of any such  primary  obligation  of the ability of the primary  obligor to make
payment of such primary obligation,  or (d) otherwise to assure or hold harmless
the holder of any such primary  obligation  against loss in respect thereof,  or
(e) to purchase or otherwise acquire,  or otherwise to assure a creditor against
loss in respect of any Indebtedness. For purposes of this definition, the amount
of any  Contingent  Obligation  shall be  deemed  to be an  amount  equal to the
maximum reasonably anticipated liability in respect thereof.

     "Contractual  Obligation"  means,  as to any Person,  any  provision of any
security  issued by such  Person  or of any  agreement,  undertaking,  contract,
indenture, mortgage, deed of trust or other instrument, document or agreement to
which such Person is a party or by which it or any of its property is bound.

     "Controlled Group" means the Parent Guarantor, the Borrower and all Persons
(whether  or not  incorporated)  under  common  control  or  treated as a single
employer  with the Parent  Guarantor,  the  Borrower or any of their  respective
Subsidiaries pursuant to Section 414(b), (c), (m) or (o) of the Code.

     "Default"  means  any  condition  or event  which  constitutes  an Event of
Default  or which  with the  giving of  notice  or lapse of time or both  would,
unless cured or waived, become an Event of Default.



                                        6





     "Disclosure  Schedule" means the Disclosure  Schedule of even date herewith
attached hereto and hereby made part of this Agreement.

     "Documentation  Agent" means Morgan  Guaranty  Trust Company of New York in
its capacity as documentation agent for the Banks hereunder,  and its successors
in such capacity.

     "dollars" means United States dollars.

     "Domestic  Business  Day" means any day except a Saturday,  Sunday or other
day on which commercial banks in New York City are authorized by law to close.

     "Domestic Lending Office" means, as to each Bank, its office located at its
address set forth in its  Administrative  Questionnaire  (or  identified  in its
Administrative  Questionnaire  as its  Domestic  Lending  Office)  or such other
office as such Bank may hereafter  designate as its Domestic  Lending  Office by
notice to the Borrower and the Administrative Agent.

     "Effective  Date"  means  the date  this  Agreement  becomes  effective  in
accordance with Section 10.09.

     "Environmental   Claim"  means  all  claims,   however  asserted,   by  any
Governmental   Authority  or  other  Person  alleging  potential   liability  or
responsibility  for  violation  of any  Environmental  Law or for  injury to the
environment or threat to public health,  personal  injury  (including  sickness,
disease or death),  property  damage,  natural  resources  damage,  or otherwise
alleging  liability  or  responsibility  for damages  (punitive  or  otherwise),
cleanup,  removal,  remedial or response costs,  restitution,  civil or criminal
penalties,  injunctive relief, or other type of relief,  resulting from or based
upon (a) the  presence,  placement,  discharge,  emission or release  (including
intentional  and   unintentional,   negligent  and   non-negligent,   sudden  or
non-sudden,  accidental or non-accidental placements, spills, leaks, discharges,
emissions  or  releases)  of any  Hazardous  Material  at, in or from  property,
whether or not owned by the Borrower, or (b) any other circumstances forming the
basis of any violation, or alleged violation, of any Environmental Law.

     "Environmental Laws" means all applicable federal, state, local and foreign
laws,  statutes,  common law duties,  judicial  decisions,  rules,  regulations,
ordinances,  judgements  and codes,  together  with all  administrative  orders,
requests,  licenses,  authorizations  and permits of, and  agreements  with, any
Governmental Authorities,  in each case relating to the environment,  health and
safety  or  to   emissions,   discharges  or  releases,   or  the   manufacture,




                                        7




distribution,  use,  treatment,  storage,  disposal,  transport or handling,  of
pollutants, contaminants, wastes or toxic or hazardous substances; including, as
they may be amended from time to time, the Comprehensive Environmental Response,
Compensation  and  Liability  Act of 1980  ("CERCLA"),  the Clean  Air Act,  the
Federal Water  Pollution  Control Act of 1972, the Solid Waste Disposal Act, the
Federal Resource Conservation and Recovery Act, the Toxic Substances Control Act
and the Emergency Planning and the Community Right-to-Know Act of 1986.

     "ERISA"  means the Employee  Retirement  Income  Security  Act of 1974,  as
amended, or any successor statute.

     "ERISA Event" means (a) a Reportable Event with respect to a Qualified Plan
or a Multiemployer  Plan; (b) a withdrawal by any member of the Controlled Group
from a Qualified  Plan  subject to Section  4063 of ERISA  during a plan year in
which it was a substantial employer (as defined in Section 4001(a)(2) of ERISA);
(c) a complete or partial  withdrawal by any member of the Controlled Group from
a  Multiemployer  Plan;  (d) the filing of a notice of intent to terminate,  the
treatment of a plan  amendment as a  termination  under Section 4041 or 4041A of
ERISA or the  commencement  of  proceedings by the PBGC to terminate a Qualified
Plan or  Multiemployer  Plan subject to Title IV of ERISA; (e) a failure to make
required  contributions to a Qualified Plan or Multiemployer  Plan; (f) an event
or condition  which might  reasonably  be expected to  constitute  grounds under
Section 4042 of ERISA for the termination of, or the appointment of a trustee to
administer,  any Qualified Plan or Multiemployer Plan; (g) the imposition of any
liability  under  Title  IV of  ERISA,  other  than  PBGC  premiums  due but not
delinquent under Section 4007 of ERISA, upon any member of the Controlled Group;
(h) an  application  for a funding  waiver or any extension of any  amortization
period  pursuant to Section 412 of the Code with respect to any Qualified  Plan;
or (i) any member of the Controlled Group engages in or otherwise becomes liable
for a non-exempt prohibited transaction.

     "Escrow  Letter" means the letter  agreement  dated March 31, 1998 from the
Borrower to the Banks and the Agents.

     "Euro-Dollar  Business  Day"  means  any  Domestic  Business  Day on  which
commercial  banks are open for  international  business  (including  dealings in
dollar deposits) in London.

     "Euro-Dollar Lending Office" means, as to each Bank, its office,  branch or
affiliate located at its address set forth in its  Administrative  Questionnaire
(or identified in its  Administrative  Questionnaire as its Euro-Dollar  Lending
Office)  or such  other  office,  branch  or  affiliate  of such  Bank as it may



                                        8




hereafter  designate as its Euro-Dollar Lending Office by notice to the Borrower
and the Administrative Agent.

     "Euro-Dollar  Loan" means (i) a Loan which bears  interest at a Euro-Dollar
Rate pursuant to the  applicable  Notice of Borrowing or Notice of Interest Rate
Election or (ii) an overdue  amount  which was a  Euro-Dollar  Loan  immediately
before it became overdue.

     "Euro-Dollar  Margin" means a rate per annum  determined in accordance with
the Pricing Schedule.

     "Euro-Dollar Rate" means a rate of interest  determined pursuant to Section
2.05(b) on the basis of an Adjusted London Interbank Offered Rate.

     "Euro-Dollar  Reserve  Percentage"  has the  meaning  set forth in  Section
2.05(b).

     "Event of Default" has the meaning set forth in Section 6.01.

     "Excess Cash Flow" means, for any fiscal year of the Borrower,  (i) the net
income of the Borrower and its  Consolidated  Subsidiaries for such fiscal year,
determined on a consolidated basis for such fiscal year, plus (ii) to the extent
deducted in determining  such net income,  the aggregate  amount of depreciation
and  amortization  and other similar non-cash charges for such fiscal year, plus
(iii) to the extent  deducted  in  determining  such net income,  the  aggregate
amount of income tax expense (other than cash taxes paid by the Borrower and its
Consolidated Subsidiaries during such fiscal year) plus (minus) (iv) the amount,
if any, of any  decrease  (increase)  in  Consolidated  Net  Working  Investment
between the  beginning and the end of such year minus (v)  Consolidated  Capital
Expenditures  for such  fiscal  year and  minus  (vi) the  aggregate  amount  of
scheduled   principal   payments  of   Indebtedness  of  the  Borrower  and  its
Consolidated Subsidiaries paid during such fiscal year by the Borrower or any of
its Consolidated Subsidiaries, determined on a consolidated basis.

     "Existing Credit  Facilities" means the $75,000,000  Credit Agreement dated
as of June 28, 1996 among AMSC Subsidiary Corporation, the Parent Guarantor, the
Banks  listed   therein,   Morgan   Guaranty  Trust  Company  of  New  York,  as
Documentation  Agent,  and Toronto  Dominion  (Texas),  Inc., as  Administrative
Agent,   together  with  the  Loan  Documents  referred  to  therein,   and  the
$150,000,000  Credit  Agreement  dated as of June 28, 1996 among AMSC Subsidiary
Corporation,  the Parent  Guarantor,  the Banks listed therein,  Morgan Guaranty


                                        9




Trust Company of New York, as Documentation Agent, and Toronto Dominion (Texas),
Inc., as  Administrative  Agent,  together with the Loan  Documents  referred to
therein.

     "FCC" means the Federal Communications Commission or any successor thereto.

     "FCC Licenses"  means the licenses  identified in the Disclosure  Schedule,
together with each other material FCC license  obtained by the Parent  Guarantor
or any Subsidiary of the Parent Guarantor.

     "Federal  Funds  Rate"  means,  for any day,  the rate per  annum  (rounded
upward,  if  necessary,  to the  nearest  1/100th  of 1%) equal to the  weighted
average of the rates on overnight Federal funds transactions with members of the
Federal  Reserve  System  arranged  by Federal  funds  brokers  on such day,  as
published by the Federal  Reserve Bank of New York on the Domestic  Business Day
next  succeeding  such  day,  provided  that (i) if such  day is not a  Domestic
Business  Day,  the  Federal  Funds Rate for such day shall be such rate on such
transactions on the next preceding  Domestic Business Day as so published on the
next succeeding  Domestic Business Day, and (ii) if no such rate is so published
on such next succeeding  Domestic  Business Day, the Federal Funds Rate for such
day shall be the average rate quoted to The Toronto-Dominion Bank on such day on
such transactions as determined by the Administrative Agent.

     "GAAP" means  generally  accepted  accounting  principles  set forth in the
opinions and pronouncements of the Accounting  Principles Board and the American
Institute of Certified Public  Accountants and statements and  pronouncements of
the Financial  Accounting Standards Board (or agencies with similar functions of
comparable stature and authority within the accounting  profession),  or in such
other  statements  by such other entity as may be in general use by  significant
segments  of  the  U.S.  accounting  profession,  which  are  applicable  to the
circumstances as of the date of determination.

     "Government  Approvals"  means  any  authorizations,  consents,  approvals,
licenses (including FCC licenses),  leases,  rulings,  permits,  tariffs, rates,
certifications, exemptions, filings or registrations by or with any Governmental
Authority required to be obtained or held by the Borrower.

     "Governmental Authority" means any nation or government, any state or other
political  subdivision  thereof,  any  central  bank  (or  similar  monetary  or
regulatory  authority) thereof,  any entity exercising  executive,  legislative,
judicial, regulatory or administrative functions of or pertaining to government,
and any  corporation  or other  entity  owned or  controlled,  through  stock or
capital ownership or otherwise, by any of the foregoing.



                                       10





     "Group of Loans" means at any time a group of Loans  consisting  of (i) all
Loans  which are Base  Rate  Loans at such  time or (ii) all  Euro-Dollar  Loans
having the same Interest  Period at such time,  provided  that, if a Loan of any
particular  Bank is converted to or made as a Base Rate Loan pursuant to Article
8, such Loan shall be included in the same Group or Groups of Loans from time to
time as it would have been in if it had not been so converted or made.

     "Guaranty  Issuance  Agreement" means the Guaranty Issuance Agreement dated
as of March 31, 1998, among Hughes, SingTel, Baron Capital, the Borrower and the
Parent Guarantor.

     "Guaranty Issuance Agreement Event of Default" has the meaning set forth in
the Guaranty Issuance Agreement.

     "Hazardous Materials" means all those substances which are regulated by, or
which may form the basis of liability under, any  Environmental  Law,  including
all  substances   identified  under  any   Environmental  Law  as  a  pollutant,
contaminant,  waste, solid waste,  hazardous  material,  hazardous  substance or
toxic  substance,  including  petroleum or any  petroleum  derived  substance or
byproduct.

     "Hughes" means Hughes Electronics Corporation, a Delaware corporation.

     "Hughes Bridge Loan Agreement"  means the Bridge Loan Agreement dated as of
December 30, 1997 by and among AMSC Subsidiary Corporation, the Parent Guarantor
and Hughes Communications Satellite Services, Inc.

     "Hughes  Guaranty" means the Guaranty,  dated as of March 31, 1998, made by
Hughes to the  Administrative  Agent for its own  benefit and the benefit of the
Banks, as the same may be amended from time to time.

     "Indebtedness"   of  any  Person  means   without   duplication,   (a)  all
indebtedness  for borrowed  money;  (b) all  obligations  issued,  undertaken or
assumed as the deferred purchase price of capital assets;  (c) all reimbursement
obligations  with  respect  to  surety  bonds,   letters  of  credit,   bankers'
acceptances  and similar  instruments  (in each case,  whether or not  matured),
excluding  performance bonds,  letters of credit and similar undertakings in the
ordinary  course  of  business  of  the  Borrower,   to  the  extent  that  such
undertakings  do not secure an  obligation  for  borrowed  money or the deferred
purchase  price of a capital  asset;  (d) all  obligations  evidenced  by notes,
bonds,  debentures or similar  instruments,  including  obligations so evidenced
incurred in connection with the  acquisition of property,  assets or businesses,
excluding  performance bonds,  letters of credit and similar undertakings in the
ordinary  course  of  business  of  the  Borrower,   to  the  extent  that  such



                                       11




undertakings  do not secure an  obligation  for  borrowed  money or the deferred
purchase price of a capital asset; (e) all indebtedness created or arising under
any  conditional  sale or  other  title  retention  agreement,  or  incurred  as
financing,  in either case with respect to property acquired by the Person (even
though the rights and remedies of the seller or bank under such agreement in the
event of default are limited to repossession or sale of such property);  (f) all
Capital  Lease  Obligations;  (g)  all  net  obligations  with  respect  to Rate
Contracts; (h) sale-leaseback  financings;  (i) all Contingent Obligations;  and
(j) all Indebtedness  referred to in paragraphs (a) through (i) above secured by
any Lien upon or in property  (including  accounts and contract rights) owned by
such  Person,  even though such Person has not assumed or become  liable for the
payment  of  such  Indebtedness.  For  purposes  of  this  definition,  (i)  any
Indebtedness  of the Borrower to the Parent  Guarantor  which is subordinated to
the  Obligations on terms and conditions  satisfactory  to the Agents,  (ii) any
Indebtedness  of the  Borrower  to a  Subsidiary  of  the  Borrower,  (iii)  any
Indebtedness  of a Subsidiary of the Borrower to or from the Borrower or another
Subsidiary of the Borrower and (iv) any Indebtedness of Sales Corporation to the
Parent  Guarantor  or the  Borrower  consisting  of loans of amounts  that would
otherwise  have been  spent by the  Borrower  in  connection  with its sales and
marketing activities shall be excluded.

     "Indemnitee" has the meaning set forth in Section 10.03(b).

     "Interest  Period" means, with respect to each Euro-Dollar Loan, the period
commencing  on the date of  borrowing  specified  in the  applicable  Notice  of
Borrowing or on the date  specified in the  applicable  Notice of Interest  Rate
Election and ending one, two,  three or six months  thereafter,  as the Borrower
may elect in the applicable notice; provided that:

     (a) any Interest  Period which would  otherwise end on a day which is not a
Euro-Dollar  Business Day shall be extended to the next  succeeding  Euro-Dollar
Business  Day unless such  Euro-Dollar  Business  Day falls in another  calendar
month,  in which  case such  Interest  Period  shall  end on the next  preceding
Euro-Dollar Business Day;

     (b) any Interest Period which begins on the last  Euro-Dollar  Business Day
of a calendar month (or on a day for which there is no numerically corresponding
day in the calendar month at the end of such Interest Period) shall,  subject to
clause (c) below, end on the last Euro-Dollar  Business Day of a calendar month;
and

     (c) any Interest  Period which would  otherwise  end after the  Termination
Date shall end on the Termination Date.


                                       12





     "Investment" means any investment in any Person,  whether by means of share
purchase,  capital contribution,  loan, Contingent  Obligation,  time deposit or
otherwise (but not including any demand deposit).

     "Joint  Venture" means any  corporation,  association,  partnership,  joint
venture or other business entity of which more than 10% but of which 50% or less
of the voting stock or other equity interests is owned or controlled directly or
indirectly by the Parent Guarantor or any of its Subsidiaries.

     "Lien"  means  any  mortgage,   deed  of  trust,   pledge,   hypothecation,
assignment,  charge or deposit  arrangement,  encumbrance,  lien  (statutory  or
other) or  preference,  priority  or other  security  interest  or  preferential
arrangement of any kind or nature  whatsoever  (including,  without  limitation,
those created by,  arising under or evidenced by any  conditional  sale or other
title  retention  agreement,  the  interest  of a lessor  under a Capital  Lease
Obligation, any financing lease having substantially the same economic effect as
any of the foregoing,  or the filing of any financing statement naming the owner
of the  asset to  which  such  lien  relates  as  debtor,  under  the UCC or any
comparable  law) and any  contingent  or other  agreement  to provide any of the
foregoing.

     "Loan"  means any  Tranche A Loan,  Tranche B Loan or  Tranche C Loan,  and
"Loans" means any or all of the foregoing, as the context may require.

     "Loan  Documents"  means this  Agreement,  each  Subsidiary  Guaranty,  the
Shareholder  Guaranties,  the Baron Capital Letter of Credit, all Rate Contracts
between the Borrower and any of the Banks and all  agreements,  instruments  and
documents executed and delivered in connection  herewith and therewith,  each as
amended, supplemented, waived or otherwise modified from time to time.

     "London  Interbank  Offered  Rate" has the  meaning  set  forth in  Section
2.05(b).

     "Major Casualty Event" means any loss of or damage to property  through one
or more related events for which the Parent Guarantor or any of its Subsidiaries
receives  any  insurance  proceeds  under any casualty  insurance  policy or any
condemnation  of property (or any transfer or disposition of property in lieu of
condemnation) for which the Parent Guarantor or any of its Subsidiaries receives
a condemnation award or other compensation,  with respect to which the aggregate
amount of such proceeds, award or other compensation exceeds $1,000,000.


                                       13





     "Major  Contractual  Obligations"  means  the  obligations  of  the  Parent
Guarantor or any Subsidiary  thereof under the ACTEL Lease Agreement and the TMI
Purchase Agreement.

     "Material Adverse Effect" means a material adverse change in, or a material
adverse effect upon, any of (a) the operations,  business, properties, condition
(financial or otherwise) of either the Parent  Guarantor  Group taken as a whole
or the  Borrower  and its  Subsidiaries  taken as a whole;  (b) the  ability  or
prospective ability of the Parent Guarantor or the Borrower to perform under any
Loan  Document  or  any  Major  Contractual  Obligation;  or (c)  the  legality,
validity, binding effect or enforceability of any Loan Document.

     "MSAT-1"  means  the  satellite  that is the  subject  of the TMI  Purchase
Agreement.

     "MSAT-2"  means  the  satellite  that is the  subject  of the  ACTEL  Lease
Agreement.

     "Multiemployer  Plan" means a  "multiemployer  plan" (within the meaning of
Section  4001(a)(3) of ERISA) to which any member of the Controlled Group makes,
is making, or is obligated to make  contributions or has made, or been obligated
to make, contributions.

     "Net Cash Proceeds"  means,  with respect to any Reduction Event, an amount
equal to the cash proceeds  (including  lease  payments)  received by the Parent
Guarantor or any of its  Subsidiaries  (excluding  the proceeds  received by any
member  of  the  Parent   Guarantor  Group  other  than  the  Borrower  and  its
Subsidiaries  to the extent the  Reduction  Percentage  (as  defined in the Term
Credit  Agreement)  thereof is applied to the prepayment of Loans (as defined in
the Term Credit  Agreement) from or in respect of such Reduction Event, less any
out-of-pocket  costs  and  expenses  (excluding   administrative   expenses  and
overhead) reasonably incurred by such Person in respect of such Reduction Event;
provided that Net Cash Proceeds shall exclude any insurance proceeds received by
the Parent  Guarantor  or any of its  Subsidiaries  in respect of the loss of or
damage  to  MSAT-2  and  required  to be paid by the  Parent  Guarantor  or such
Subsidiary to ACTEL or its permitted assigns;  provided,  further, that Net Cash
Proceeds  received by the Parent Guarantor or any of its Subsidiaries in respect
of any period  under the ACTEL  Lease  Agreement  shall be reduced by the amount
paid by the Parent Guarantor or such Subsidiary during such period under the TMI
Purchase  Agreement  and,  without  duplication,  the amount  paid by the Parent
Guarantor  or such  Subsidiary  during  such  period  for up to  $50,000,000  of
insurance  for MSAT-1  required  to be  obtained  hereunder  or  required  to be
obtained by the Shareholder Guarantors.


                                       14





     "Notes" means promissory  notes of the Borrower,  substantially in the form
of Exhibit A hereto,  evidencing  the  obligation  of the  Borrower to repay the
Loans, and "Note" means any one of such promissory notes issued hereunder.

     "Notice of Borrowing" has the meaning set forth in Section 2.02(a).

     "Notice of  Interest  Rate  Election"  has the meaning set forth in Section
2.08(a).

     "Notice of Lien" means any "notice of lien" or similar document intended to
be filed or recorded with any court, registry, recorder's office, central filing
office or  Governmental  Authority  for the  purpose  of  evidencing,  creating,
perfecting or preserving the priority of a Lien securing  obligations owing to a
Governmental Authority.

     "Obligations"  means all Loans, and other  Indebtedness,  advances,  debts,
liabilities,  and obligations,  owing by the Borrower to any Bank, any Agent, or
any other Person required to be indemnified under any Loan Document, of any kind
or nature,  present or future, whether or not evidenced by any note, guaranty or
other instrument,  arising under this Agreement,  under any other Loan Document,
whether  or not for the  payment  of  money,  whether  arising  by  reason of an
extension of credit,  loan,  guaranty,  indemnification  or in any other manner,
whether direct or indirect (including those acquired by assignment), absolute or
contingent,  due or to become due, now existing or hereafter arising and however
acquired.

     "Offering Memorandum" means the Preliminary Offering Memorandum dated March
9, 1998  relating to units  consisting  of Senior Notes and warrants to purchase
common stock of the Parent Guarantor.

     "Parent" means, with respect to any Bank, any Person controlling such Bank.

     "Parent Guarantor" means American Mobile Satellite Corporation,  a Delaware
corporation, and its successors.

     "Parent  Guarantor  Group" means the Parent  Guarantor and its Consolidated
Subsidiaries.

     "Participant" has the meaning set forth in Section 10.06(b).

     "PBGC"  means  the  Pension  Benefit  Guaranty  Corporation  or any  entity
succeeding to any or all of its functions under ERISA.


                                       15





     "Permitted Liens" has the meaning set forth in Section 5.15.

     "Person" means an individual, a corporation, a limited liability company, a
partnership,  an  association,  a trust or any  other  entity  or  organization,
including a government or political  subdivision or an agency or instrumentality
thereof.

     "Plan" means an employee benefit plan (as defined in Section 3(3) of ERISA)
which any member of the  Controlled  Group sponsors or maintains or to which any
member of the Controlled Group makes or is obligated to make  contributions  and
includes any Multiemployer Plan or Qualified Plan.

     "Pricing Schedule" means the Pricing Schedule attached hereto.

     "Prime  Rate"  means  the  rate  of  interest  publicly  announced  by  The
Toronto-Dominion Bank in New York City from time to time as its Prime Rate.

     "Principal  Subsidiary"  means  at any time any  Subsidiary  of the  Parent
Guarantor, except Subsidiaries (other than the Borrower) which at such time have
been designated by the Parent Guarantor (by notice to the Administrative  Agent,
which may be amended from time to time) as nonmaterial  and which, if aggregated
and  considered  as a single  subsidiary,  would  not meet the  definition  of a
"significant  subsidiary"  contained as of the date hereof in Regulation  S-X of
the Securities and Exchange Commission.

     "Qualified Plan" means a pension plan (as defined in Section 3(2) of ERISA)
intended  to be  tax-qualified  under  Section  401(a) of the Code and which any
member of the Controlled Group sponsors,  maintains,  or to which it makes or is
obligated to make contributions or has made contributions at any time during the
immediately  preceding  period  covering  at  least  five (5)  plan  years,  but
excluding any Multiemployer Plan.

     "Quarterly Date" means March 31, June 30, September 30 and December 31.

     "Rate  Contracts"  means interest rate and currency swap  agreements,  cap,
floor and collar agreements,  interest rate insurance, currency spot and forward
contracts and other  agreements or arrangements  designed to provide  protection
against fluctuations in interest or currency exchange rates;  provided that such
agreements or arrangements are documented under master netting agreements.

     "Reduction Event" means (i) any Asset Sale, (ii) the issuance of any equity
securities by the Parent Guarantor or any of its Subsidiaries (other than equity



                                       16




securities (x) issued pursuant to any stock option, stock purchase or other plan
intended to benefit or compensate  the  officers,  directors or employees of the
Parent  Guarantor,  the Borrower or any  Principal  Subsidiary,  but only to the
extent  that the Net Cash  Proceeds  thereof  in any  fiscal  year of the Parent
Guarantor do not exceed the sum of (A) $2,000,000 plus (B) the aggregate  amount
by which such Net Cash Proceeds  were less than  $2,000,000 in each prior fiscal
year of the Parent  Guarantor  after the date  hereof,  (y) issued to the Parent
Guarantor or any of its  Subsidiaries  or (z) issued by AMRC  Holdings or any of
its  Subsidiaries)  or (iii)  the  occurrence  of a Major  Casualty  Event.  The
description of any  transaction as falling within the above  definition does not
affect  any  limitation  on  such  transaction  imposed  by  Article  5 of  this
Agreement.

     "Reduction  Percentage"  means (i) in respect of an Asset Sale  (other than
the Satellite  Lease  Arrangements)  or a Major Casualty  Event,  100%,  (ii) in
respect of the Satellite Lease  Arrangements,  100% for the first $25,000,000 of
Net Cash Proceeds with respect  thereto and 75% for any such additional Net Cash
Proceeds,  (iii) in respect of Excess Cash Flow,  100% or (iv) in respect of the
issuance  of  equity  securities  (other  than  (x) to a  member  of the  Parent
Guarantor Group or (y) to a Shareholder Guarantor as part of a private placement
to one or more Shareholder Guarantors) by the Parent Guarantor or any Subsidiary
thereof, 50%.

     "Reference  Banks" means the principal  London  offices of Morgan  Guaranty
Trust Company of New York, The Toronto-Dominion Bank and any other Bank which is
appointed a Reference Bank by the Agents after  consultation  with the Borrower,
and "Reference Bank" means any one of such Reference Banks.

     "Regulation U" means  Regulation U of the Board of Governors of the Federal
Reserve System, as in effect from time to time.

     "Reportable  Event"  means any of the events  set forth in Section  4043 of
ERISA or the  regulations  thereunder,  a  withdrawal  from a Plan  described in
Section 4063 of ERISA, or a cessation of operations described in Section 4062(e)
of ERISA.

     "Required  Banks"  means  at any time  Banks  having  more  than 50% of the
aggregate  amount of the  Commitments  or, if the  Commitments  shall  have been
terminated,  holding  Notes  evidencing  more than 50% of the  aggregate  unpaid
principal amount of the Loans.

     "Requirement  of  Law"  means,  as to any  Person,  any law  (statutory  or
common),  treaty,  rule or regulation or  determination of an arbitrator or of a
Governmental Authority, in each case applicable to or binding upon the Person or
any of its property or to which the Person or any of its property is subject; in



                                       17




any case,  non-compliance  with which by either of the Parent  Guarantor  or the
Borrower or their  Subsidiaries  could reasonably be expected to have a Material
Adverse Effect.

     "Responsible  Officer"  means,  with  respect  to  any  Person,  the  Chief
Executive  Officer,  the President or a duly  authorized Vice President or, with
respect to financial matters,  the Chief Financial Officer or the Treasurer,  of
such Person.

     "Sales  Corporation" means American Mobile Satellite Sales  Corporation,  a
Delaware corporation.

     "Satellite Lease  Arrangements"  means the sale or lease of MSAT-2 pursuant
to the ACTEL Agreement or a replacement  agreement (an "MSAT-2 Lease Agreement")
provided that any such replacement agreement shall be on commercially reasonable
terms,  and  provided  that (A) the  consideration  received by the  Borrower in
respect of such sale or lease (x)  consists  solely of cash and (y)  constitutes
fair market value (as  determined  by the Board of Directors of the Borrower set
forth in a resolution  thereof  delivered  to the  Administrative  Agent,  which
determination shall be based upon an opinion or appraisal issued by an appraisal
or investment  banking firm of national  standing);  (B) the Borrower shall have
acquired  (through  purchase  or  lease)  capacity  on  MSAT-1  or a  reasonable
substitute  thereof either (x) pursuant to the TMI Purchase Agreement or (y) any
other  agreement  with a term not less than the maximum term of the MSAT-2 Lease
Agreement then in effect and otherwise on commercially  reasonable  terms if (in
the  case  of  this  clause  (y))  in the  opinion  of a  nationally  recognized
independent  expert  (a) the  capacity  acquired  pursuant  to such  replacement
agreement  is  sufficient  to permit the Borrower to conduct its  operations  as
conducted  and as  contemplated  to be conducted  through the term of the MSAT-2
Lease  Agreement  then in  effect  and (b) the total  consideration  paid by the
Borrower  for such  replacement  satellite  capacity is no greater than the fair
market value thereof.

     "Senior Notes" means the Borrower's 12 1/4% Senior Notes due 2008.

     "Shareholder Guarantor Security Agreement" means the Reimbursement Security
and Pledge Agreement dated as of March 31, 1998 between the Parent Guarantor and
Hughes.

     "Shareholder Guarantors" means Hughes, SingTel and Baron Capital.

     "Shareholder  Guaranties"  means the Hughes Guaranty,  the SingTel Guaranty
and the Baron Capital Guaranty.



                                       18





     "SingTel" means Singapore  Telecommunications Ltd., a corporation organized
under the laws of Singapore.

     "SingTel Guaranty" means the Guaranty,  dated as of March 31, 1998, made by
SingTel to the  Administrative  Agent for its own benefit and the benefit of the
Banks, as the same may be amended from time to time.

     "Subsidiary"  means,  as to any Person,  any corporation or other entity of
which  securities or other ownership  interests  having ordinary voting power to
elect a majority of the board of directors or other persons  performing  similar
functions are at the time directly or indirectly owned by such Person.

     "Subsidiary   Guaranty"   means  each  Subsidiary   Guaranty   between  the
Administrative Agent and a Subsidiary of the Borrower, substantially in the form
of Exhibit E hereto.

     "Term Credit  Agreement"  means the Term Credit  Agreement  dated as of the
date  hereof  among the Parent  Guarantor,  the Agents and the other banks party
thereto,  as the  same  may be  amended,  supplemented,  restated  or  otherwise
modified from time to time.

     "Termination  Date"  means  March  31,  2003,  or,  if  such  day  is not a
Euro-Dollar  Business Day, the next succeeding  Euro-Dollar  Business Day unless
such Euro-Dollar Business Day falls in another calendar month, in which case the
Termination Date shall be the next preceding Euro-Dollar Business Day.

     "TMI Purchase Agreement" means the Satellite Purchase Agreement dated as of
December 4, 1997 between TMI Communications and Company, Limited Partnership and
the Parent Guarantor.

     "Tranche A  Commitment"  means (i) with  respect to each Bank listed on the
Commitment  Schedule,  the amount set forth  opposite its name under the heading
"Tranche A Commitments" in the Commitment  Schedule and (ii) with respect to any
Assignee,  the amount of the transferor Bank's Tranche A Commitment  assigned to
such  Assignee  pursuant  to Section  10.06,  in each case as such amount may be
reduced  from time to time  pursuant  to  Section  2.07 or 2.09 or  changed as a
result of an assignment pursuant to Section 10.06.

     "Tranche B  Commitment"  means (i) with  respect to each Bank listed on the
Commitment  Schedule,  the amount set forth  opposite its name under the heading
"Tranche B Commitments" in the Commitment  Schedule and (ii) with respect to any
Assignee,  the amount of the transferor Bank's Tranche B Commitment  assigned to



                                       19




such  Assignee  pursuant  to Section  10.06,  in each case as such amount may be
reduced  from time to time  pursuant  to  Section  2.07 or 2.09 or  changed as a
result of an assignment pursuant to Section 10.06.

     "Tranche C  Commitment"  means (i) with  respect to each Bank listed on the
Commitment  Schedule,  the amount set forth  opposite its name under the heading
"Tranche C Commitments" in the Commitment  Schedule and (ii) with respect to any
Assignee,  the amount of the transferor Bank's Tranche C Commitment  assigned to
such  Assignee  pursuant  to Section  10.06,  in each case as such amount may be
reduced  from time to time  pursuant  to  Section  2.07 or 2.09 or  changed as a
result of an assignment pursuant to Section 10.06.

     "Tranche A Loan" means a loan made by a Bank  pursuant to Section 2.01 as a
Tranche A Loan.

     "Tranche B Loan" means a loan made by a Bank  pursuant to Section 2.01 as a
Tranche B Loan.

     "Tranche C Loan" means a loan made by a Bank  pursuant to Section 2.01 as a
Tranche C Loan.

     "Type", when used in reference to any Loan or Borrowing,  refers to whether
the rate of interest on such Loan, or on the Loans  compromising such Borrowing,
is determined by reference to the Euro-Dollar Rate or the Base Rate.

     "UCC" means the Uniform Commercial Code as in effect in any jurisdiction.

     "Unfunded  Pension  Liabilities"  means  the  excess  of a  Plan's  accrued
benefits,  as defined in Section 3(23) of ERISA,  over the current value of that
Plan's assets, as defined in Section 3(26) of ERISA.

     "United  States" means the United  States of America,  including the States
and the District of Columbia, but excluding its territories and possessions.

     "Vendor Financing  Indebtedness" means Indebtedness incurred by a member of
the Parent  Guarantor Group the proceeds of which are utilized solely to acquire
ground-based Communications Assets.

     "Withdrawal Liabilities" means, as of any determination date, the aggregate
amount of the  liabilities,  if any,  pursuant  to Section  4201 of ERISA if the
Controlled Group made a complete withdrawal from all Multiemployer Plans and any
increase in contributions pursuant to Section 4243 of ERISA.


                                       20





     SECTION  1.02.  Accounting  Terms  and  Determinations.   Unless  otherwise
specified  herein,  all accounting  terms used herein shall be interpreted,  all
accounting  determinations hereunder shall be made, and all financial statements
required to be delivered  hereunder shall be prepared in accordance with GAAP as
in effect from time to time,  applied on a basis consistent  (except for changes
concurred in by the Parent  Guarantor's  and the Borrower's  independent  public
accountants)  with the most recent audited  consolidated  or combined  financial
statements  of each the  Parent  Guarantor,  the Parent  Guarantor  Group or the
Borrower and its Consolidated Subsidiaries, as the case may be, delivered to the
Banks;  provided  that,  if the Parent  Guarantor or the  Borrower  notifies the
Administrative  Agent that it wishes to amend the  definition  of  "Excess  Cash
Flow" in Section 1.01 or any  covenant in Article 5 to  eliminate  the effect of
any change in GAAP on the operation of such  covenant (or if the  Administrative
Agent  notifies the Parent  Guarantor and the Borrower  that the Required  Banks
wish to amend  Section  1.01 or  Article 5 for such  purpose),  then the  Parent
Guarantor's and the Borrower's compliance with such covenant shall be determined
on the basis of GAAP in effect  immediately  before the relevant  change in GAAP
became  effective,  until either such notice is  withdrawn  or such  covenant is
amended in a manner  satisfactory to the Parent Guarantor,  the Borrower and the
Required Banks.



                                    ARTICLE 2
                                   THE CREDITS

     SECTION 2.01.  Commitments to Lend.  During the Availability  Period,  each
Bank severally  agrees, on the terms and conditions set forth in this Agreement,
to lend to the Borrower from time to time amounts not to exceed in the aggregate
the amount of its Commitments.  Each Borrowing under this Section shall be in an
aggregate  principal  amount of $5,000,000 or any larger  multiple of $1,000,000
(except that any such  Borrowing  may be in the  aggregate  amount of the unused
Commitments),  shall be made from the several  Banks  ratably in  proportion  to
their respective  Commitments and shall be made by each Bank as Tranche A Loans,
Tranche B Loans and  Tranche C Loans  ratably  in  proportion  to its  Tranche A
Commitment,  Tranche B Commitment and Tranche C Commitment. Within the foregoing
limits,  the Borrower may borrow under this Section,  prepay Loans to the extent
permitted  by Section  2.10 and  reborrow  at any time  during the  Availability
Period under this Section.

     SECTION  2.02.  Method  of  Borrowing.  (a) The  Borrower  shall  give  the
Administrative  Agent irrevocable  telephonic notice,  confirmed  immediately in




                                       21




writing  (a  "Notice of  Borrowing"),  not later than 10:30 A.M.  (New York City
time) on (x) the Domestic  Business Day before each Base Rate  Borrowing and (y)
the  third   Euro-Dollar   Business  Day  before  each  Euro-Dollar   Borrowing,
specifying:

          (i) the date of such Borrowing, which shall be a Domestic Business Day
          in the case of a Base Rate Borrowing or a Euro-Dollar  Business Day in
          the case of a Euro-Dollar Borrowing;

          (ii) the aggregate amount of such Borrowing;

          (iii) whether the Loans comprising such Borrowing are to bear interest
          initially at the Base Rate or a Euro-Dollar Rate; and

          (iv) in the  case of a  Euro-Dollar  Borrowing,  the  duration  of the
          Interest Period applicable  thereto,  subject to the provisions of the
          definition of Interest Period.

In no  event  shall  the  total  number  of  Groups  of  Loans  at any one  time
outstanding  exceed ten,  and each Group of Loans shall at all times  consist of
Tranche A Loans,  Tranche B Loans and  Tranche C Loans of the Banks  ratably  in
proportion to their respective Tranche A Commitments,  Tranche B Commitments and
Tranche C Commitments.

     (b) Upon receipt of a Notice of Borrowing,  the Administrative  Agent shall
promptly notify each Bank of the contents thereof,  of such Bank's ratable share
of such Borrowing and of the portion  thereof which shall be made as a Tranche A
Loan, a Tranche B Loan and a Tranche C Loan.

     (c) Not later  than  12:00  Noon  (New York City  time) on the date of each
Borrowing,  each Bank shall make available its ratable share of such  Borrowing,
in  Federal  or other  funds  immediately  available  in New York  City,  to the
Administrative  Agent at its  address  referred to in Section  5.03.  Unless the
Administrative  Agent  determines  that any  applicable  condition  specified in
Article 3 has not been satisfied,  the Administrative  Agent will make the funds
so received  from the Banks  available  to the  Borrower  at the  Administrative
Agent's aforesaid address.

     (d) Unless the Administrative  Agent shall have received notice from a Bank
prior to the date of any Borrowing that such Bank will not make available to the
Administrative  Agent such Bank's share of such  Borrowing,  the  Administrative
Agent  may  assume  that  such  Bank  has  made  such  share  available  to  the
Administrative Agent on the date of such Borrowing in accordance with subsection




                                       22




(c) of this  Section and the  Administrative  Agent may,  in reliance  upon such
assumption,  make available to the Borrower on such date a corresponding amount.
If and to the extent that such Bank shall not have so made such share  available
to the Administrative Agent, such Bank and the Borrower severally agree to repay
to the  Administrative  Agent  forthwith  on demand  such  corresponding  amount
together with interest  thereon,  for each day from the date such amount is made
available  to  the  Borrower  until  the  date  such  amount  is  repaid  to the
Administrative Agent, at (i) in the case of the Borrower, a rate per annum equal
to the higher of the Federal Funds Rate and the interest rate applicable thereto
pursuant to Section  2.05 and (ii) in the case of such Bank,  the Federal  Funds
Rate. If such Bank shall repay to the  Administrative  Agent such  corresponding
amount, such amount so repaid shall constitute such Bank's Loan included in such
Borrowing for purposes of this Agreement.

     SECTION 2.03. Notes. (a) The Tranche A Loans, Tranche B Loans and Tranche C
Loans of each Bank shall each be evidenced by a single Note payable to the order
of such Bank for the account of its Applicable Lending Office in an amount equal
to the aggregate unpaid principal amount of such Bank's Tranche A Loans, Tranche
B Loans  and  Tranche  C  Loans,  as the  case may be.  Each  reference  in this
Agreement  to the  "Notes" of a Bank shall be deemed to refer to and include any
or all of the Notes of such Bank  described in this Section,  as the context may
require.

     (b) Each Bank may, by notice to the Borrower and the Administrative  Agent,
request  that its  Tranche A Loans,  Tranche  B Loans  and  Tranche C Loans of a
particular  Type be  evidenced  by a  separate  Note in an  amount  equal to the
aggregate  unpaid  principal  amount of such  Loans.  Each such Note shall be in
substantially  the form of Exhibit A hereto with  appropriate  modifications  to
reflect the fact that it evidences solely Loans of the relevant Type.

     (c) Upon  receipt of each Bank's  Notes  pursuant to Section  3.01(a),  the
Documentation  Agent  shall  forward  such Notes to such  Bank.  Each Bank shall
record the date, amount and Type of each Loan made by it and the date and amount
of each payment of principal  made by the Borrower  with respect  thereto on the
appropriate  Note,  and may,  if such  Bank so  elects  in  connection  with any
transfer or enforcement of any of its Notes,  endorse on the schedule  forming a
part thereof  appropriate  notations to evidence the foregoing  information with
respect to each Loan then outstanding  thereunder;  provided that the failure of
any Bank to make any such  recordation  or  endorsement  shall  not  affect  the
obligations  of the Borrower  hereunder or under the Notes.  Each Bank is hereby
irrevocably  authorized by the Borrower so to endorse its Notes and to attach to
and make a part of its Notes a  continuation  of any such  schedule  as and when
required.


                                       23





     SECTION 2.04.  Maturity of Loans. Any Loans  outstanding on the Termination
Date (together with accrued  interest  thereon) shall be due and payable on such
date.

     SECTION 2.05.  Interest Rates.  (a) Each Base Rate Loan shall bear interest
on the outstanding  principal  amount  thereof,  for each day from the date such
Loan is made until it becomes  due,  at a rate per annum  equal to the Base Rate
for such day.  Such  interest  shall be  payable  quarterly  in  arrears on each
Quarterly  Date and, with respect to the principal  amount of any Base Rate Loan
converted to a Euro-Dollar  Loan, on each date a Base Rate Loan is so converted.
Any overdue  principal of or interest on any Base Rate Loan shall bear interest,
payable on demand,  for each day until paid at a rate per annum equal to the sum
of 2% plus the rate otherwise applicable to Base Rate Loans for such day.

     (b) Each Euro-Dollar Loan shall bear interest on the outstanding  principal
amount thereof,  for each day during each Interest Period applicable thereto, at
a rate per annum  equal to the sum of the  Euro-Dollar  Margin for such day plus
the Adjusted London  Interbank  Offered Rate applicable to such Interest Period.
Such interest shall be payable for each Interest  Period on the last day thereof
and, if such Interest Period is longer than three months,  at intervals of three
months after the first day thereof.

     The "Adjusted  London  Interbank  Offered Rate"  applicable to any Interest
Period means a rate per annum equal to the quotient obtained (rounded upward, if
necessary,  to the next higher  1/10,000 of 1%) by dividing  (i) the  applicable
London  Interbank  Offered  Rate by (ii)  1.00  minus  the  Euro-Dollar  Reserve
Percentage.

     The "London Interbank Offered Rate" applicable to any Interest Period means
the average (rounded upward, if necessary, to the next higher 1/16 of 1%) of the
respective  rates per annum at which  deposits in dollars are offered to each of
the Reference Banks in the London interbank  market at approximately  11:00 A.M.
(London  time)  two  Euro-Dollar  Business  Days  before  the  first day of such
Interest Period in an amount  approximately equal to the principal amount of the
Euro-Dollar  Loan of such  Reference  Bank to which such  Interest  Period is to
apply and for a period of time comparable to such Interest Period.

     "Euro-Dollar   Reserve  Percentage"  means  for  any  day  that  percentage
(expressed  as a decimal)  which is in effect on such day, as  prescribed by the
Board  of  Governors  of the  Federal  Reserve  System  (or any  successor)  for
determining  the maximum  reserve  requirement  for a member bank of the Federal
Reserve System in New York City with deposits  exceeding five billion dollars in



                                       24




respect of  "Eurocurrency  liabilities"  (or in respect of any other category of
liabilities  which includes  deposits by reference to which the interest rate on
Euro-Dollar Loans is determined or any category of extensions of credit or other
assets which includes loans by a non-United  States office of any Bank to United
States residents).  The Adjusted London Interbank Offered Rate shall be adjusted
automatically  on and as of the effective date of any change in the  Euro-Dollar
Reserve Percentage.

     (c) Any overdue principal of or interest on any Euro-Dollar Loan shall bear
interest,  payable on demand,  for each day until paid at a rate per annum equal
to the higher of (i) the sum of 2% plus the Euro-Dollar Margin for such day plus
the quotient obtained (rounded upward, if necessary, to the next higher 1/10,000
of 1%) by dividing (x) the average  (rounded upward,  if necessary,  to the next
higher  1/16 of 1%) of the  respective  rates per annum at which one day (or, if
such amount due remains unpaid more than three  Euro-Dollar  Business Days, then
for such other  period of time not longer than six months as the  Administrative
Agent may select) deposits in dollars in an amount  approximately  equal to such
overdue payment due to each of the Reference Banks are offered to such Reference
Bank in the London  interbank  market for the  applicable  period  determined as
provided above by (y) 1.00 minus the Euro-Dollar  Reserve Percentage (or, if the
circumstances  described in clause (a) or (b) of Section 8.01 shall exist,  at a
rate per  annum  equal to the sum of 2% plus the rate  applicable  to Base  Rate
Loans for such day) and (ii) the sum of 2% plus the Euro-Dollar  Margin for such
day plus the Adjusted London  Interbank  Offered Rate applicable to such Loan at
the date such payment was due.

     (d) The Administrative  Agent shall determine each interest rate applicable
to the Loans hereunder. The Administrative Agent shall give prompt notice to the
Borrower and the participating Banks of each rate of interest so determined, and
its determination thereof shall be conclusive in the absence of manifest error.

     (e)  Each  Reference  Bank  agrees  to use  its  best  efforts  to  furnish
quotations to the Administrative  Agent as contemplated by this Section.  If any
Reference Bank does not furnish a timely  quotation,  the  Administrative  Agent
shall  determine  the relevant  interest  rate on the basis of the  quotation or
quotations  furnished by the  remaining  Reference  Bank or Banks or, if none of
such  quotations is available on a timely basis,  the provisions of Section 8.01
shall apply.

     SECTION 2.06. Commitment Fees. During the Availability Period, the Borrower
shall pay to the  Administrative  Agent for the account of the Banks  ratably in
proportion to their  Commitments a commitment  fee equal to the  Commitment  Fee




                                       25




Percentage  per annum of the daily amount by which the  aggregate  amount of the
Commitments  exceeds the aggregate  outstanding  principal  amount of the Loans.
Such  commitment  fee shall accrue from and including the Effective  Date to but
excluding the date of termination  of the  Commitments  in their  entirety,  and
shall be payable  quarterly in arrears on each Quarterly Date and on the date of
termination of the  Commitments in their  entirety.  Any overdue fees shall bear
interest,  payable on demand,  for each day until paid at a rate per annum equal
to the sum of 2% plus the rate otherwise  applicable to Base Rate Loans for such
day.

     SECTION 2.07. Optional Termination or Reduction of Commitments.  (a) During
the Availability Period, the Borrower may, upon at least three Domestic Business
Days' notice to the  Administrative  Agent, (i) terminate the Commitments at any
time, if no Loans are outstanding at such time, or (ii) ratably reduce from time
to time by an aggregate amount of $5,000,000 or a larger multiple of $1,000,000,
the aggregate  amount of the Commitments in excess of the aggregate  outstanding
principal  amount of the Loans.  Each reduction of Commitments  pursuant to this
Section 2.07 shall be applied  ratably to the respective  Tranche A Commitments,
Tranche B Commitments and Tranche C Commitments of the Banks.

     (b) Upon receipt of a notice of  reduction  pursuant to this  Section,  the
Administrative Agent shall promptly notify each Bank of the contents thereof, of
such  Bank's  ratable  share  of  such  reduction  and  of the  portion  thereof
applicable to the Tranche A  Commitments,  Tranche B  Commitments  and Tranche C
Commitments, and such notice shall not thereafter be revocable by the Borrower.

     SECTION 2.08.  Method of Electing Interest Rates. (a) The Loans included in
each  Borrowing  shall bear interest  initially at the type of rate specified by
the Borrower in the applicable Notice of Borrowing. Thereafter, the Borrower may
from time to time elect to change or continue the type of interest rate borne by
each Group of Loans  (subject in each case to the  provisions  of Article 8), as
follows:

               (i) if such Loans are Base Rate Loans,  the Borrower may elect to
               convert  such Loans to  Euro-Dollar  Loans as of any  Euro-Dollar
               Business Day and

               (ii) if such Loans are Euro-Dollar  Loans, the Borrower may elect
               to convert  such  Loans to Base Rate  Loans or elect to  continue
               such  Loans  as  Euro-Dollar  Loans  for an  additional  Interest
               Period,  subject  to  Section  2.12  in  the  case  of  any  such
               conversion  or  continuation  effective on any day other than the
               last day of the then current  Interest Period  applicable to such
               Loans.


                                       26






Each  such  election  shall be made by  giving  irrevocable  telephonic  notice,
confirmed  immediately in writing (a "Notice of Interest Rate  Election") to the
Administrative Agent not later than 10:30 A.M. (New York City time) on the third
Euro-Dollar Business Day before the conversion or continuation  selected in such
notice is to be  effective.  A Notice of Interest  Rate  Election  may, if it so
specifies,  apply to only a portion  of the  aggregate  principal  amount of the
relevant  Group of Loans;  provided  that (i) such portion is allocated  ratably
among the Loans  comprising such Group and (ii) the portion to which such Notice
applies,  and the  remaining  portion  to  which  it does  not  apply,  are each
$5,000,000 or any larger multiple of $1,000,000.

     (b) Each Notice of Interest Rate Election shall specify:

               (i) the  Group of Loans  (or,  subject  to the last  sentence  of
               Section 2.02(a), portion thereof) to which such notice applies;

               (ii) the date on which the conversion or continuation selected in
               such  notice is to be  effective,  which  shall  comply  with the
               applicable clause of subsection (a) above;

               (iii) if the Loans comprising such Group are to be converted, the
               new Type of Loans and,  if the Loans  being  converted  are to be
               Euro-Dollar  Loans, the duration of the next succeeding  Interest
               Period applicable thereto; and

               (iv) if such Loans are to be continued as  Euro-Dollar  Loans for
               an additional  Interest  Period,  the duration of such additional
               Interest Period.

Each  Interest  Period  specified in a Notice of Interest  Rate  Election  shall
comply with the  provisions of the  definition  of Interest  Period set forth in
Section 1.01.

     (c) If,  upon the  expiration  of any  Interest  Period  applicable  to any
Eurodollar  Loan,  the Borrower has not given a timely  Notice of Interest  Rate
Election with respect to such Loan, the Administrative  Agent shall be deemed to
have  received a Notice of Interest Rate Election from the Borrower with respect
to such Loan requesting that such Loan be converted into a Base Rate Loan on the
last day of the Interest Period applicable to such Loan.

     (d) Upon receipt of a Notice of Interest  Rate  Election  from the Borrower
pursuant  to  subsection  (a) above or a deemed  receipt of a Notice of Interest



                                       27




Rate Election pursuant to subsection (c) above, the  Administrative  Agent shall
promptly  notify each Bank of the  contents  thereof  and such notice  shall not
thereafter be revocable by the Borrower.

     (e) An election by the  Borrower to change or continue the rate of interest
applicable to any Group of Loans pursuant to this Section shall not constitute a
"Borrowing" subject to the provisions of Section 3.02.

     SECTION 2.09. Mandatory  Termination and Reduction of Commitments.  (a) The
Commitments shall terminate on the last day of the Availability Period.

     (b) On each Commitment  Reduction Date, the Commitments shall be reduced by
$10,000,000;  provided that if, during the 90-day period ending on and including
such Commitment Reduction Date, the Commitments shall have been reduced pursuant
to clause (c) below,  the  Commitments  shall be reduced only by the amount,  if
any, by which  $10,000,000  is greater than the amount by which the  Commitments
were reduced during such 90-day period pursuant to clause (c) below.

     (c) In addition:

               (i)  in  the  event  that  the  Parent  Guarantor  or  any of its
               Subsidiaries  shall at any time,  or from  time to time,  receive
               after the date  hereof  any Net Cash  Proceeds  of any  Reduction
               Event, the Commitments shall be reduced by an amount equal to the
               Reduction  Percentage  of such Net Cash  Proceeds  on the date of
               receipt of such Net Cash Proceeds; and

               (ii) on each date on which the Borrower is required to notify the
               Administrative  Agent of the Excess Cash Flow for any fiscal year
               pursuant to Section 5.02(b),  the Commitments shall be reduced by
               an amount equal to the  Reduction  Percentage of Excess Cash Flow
               for such fiscal year.

     (d) Each reduction of Commitments pursuant to this Section shall be applied
ratably to the  respective  Tranche A  Commitments,  Tranche B  Commitments  and
Tranche  C  Commitments  of  the  Banks.  The  amount  of any  reduction  of the
Commitments  pursuant to Section 2.07 or subsection (c) of this Section shall be
applied  to  reduce  the  amount  of  subsequent  scheduled  reductions  of  the
Commitments  pursuant  to  subsections  (a) and (b)  above in  inverse  order of
maturity;  provided that if the Commitments  are reduced  pursuant to subsection
(c) above  less than 90 days  prior to a  Commitment  Reduction  Date,  then the
portion,  if any, of such reduction not greater than (i)  $10,000,000  less (ii)
the aggregate amount of similar  reductions made less than 90 days prior to such
Commitment Reduction Date shall be applied in direct order of maturity.


                                       28





     (e) On the date of any reduction of the Commitments  pursuant to subsection
(b) or (c) above,  the Borrower shall repay such principal amount of each Bank's
outstanding Tranche A Loans, Tranche B Loans and Tranche C Loans, if any, as may
be necessary so that after such  repayment the aggregate  outstanding  principal
amount of such Bank's Tranche A Loans,  Tranche B Loans and Tranche C Loans does
not exceed the amount of such Bank's Tranche A Commitments, Tranche B Commitment
and  Tranche  C  Commitment  as  so  reduced.   The  Borrower   shall  give  the
Administrative  Agent at least five  Euro-Dollar  Business  Days' notice of each
prepayment of Euro-Dollar Loans required pursuant to this subsection.

     SECTION  2.10.  Optional  Prepayments.  (a)  Subject  in  the  case  of any
Euro-Dollar  Borrowing  to Section  2.12,  the Borrower  may,  upon at least one
Domestic Business Day's notice to the Administrative  Agent, prepay any Group of
Base Rate Loans, or upon at least three Euro-Dollar Business Days' notice to the
Administrative  Agent,  prepay any Group of Euro-Dollar  Loans,  in each case in
whole  at any  time,  or from  time to  time  in  part  in  amounts  aggregating
$5,000,000 or any larger multiple of $1,000,000,  by paying the principal amount
to be prepaid  together with accrued interest thereon to the date of prepayment.
Each such optional  prepayment  shall be applied to prepay ratably the Tranche A
Loans, Tranche B Loans and Tranche C Loans of the several Banks included in such
Group.

     (b) Upon receipt of a notice of prepayment  pursuant to this  Section,  the
Administrative Agent shall promptly notify each Bank of the contents thereof and
of such  Bank's  ratable  share of such  prepayment  and such  notice  shall not
thereafter be revocable by the Borrower.

     SECTION 2.11.  General  Provisions as to Payments.  (a) The Borrower  shall
make each  payment  of  principal  of,  and  interest  on, the Loans and of fees
hereunder,  not later than 12:00 Noon (New York City time) on the date when due,
in  Federal  or other  funds  immediately  available  in New York  City,  to the
Administrative   Agent  at  its  address   referred  to  in  Section  5.03.  The
Administrative  Agent will promptly distribute to each Bank its ratable share of
each such payment  received by the  Administrative  Agent for the account of the
Banks, to be applied ratably to the Tranche A Loans, the Tranche B Loans and the
Tranche C Loans of the Banks.  Whenever any payment of principal of, or interest
on, the Base Rate Loans or of fees shall be due on a day which is not a Domestic
Business  Day,  the date for  payment  thereof  shall  be  extended  to the next
succeeding  Domestic  Business  Day.  Whenever any payment of  principal  of, or
interest  on,  the  Euro-Dollar  Loans  shall  be  due on a day  which  is not a
Euro-Dollar  Business Day, the date for payment thereof shall be extended to the




                                       29




next succeeding  Euro-Dollar  Business Day unless such Euro-Dollar  Business Day
falls in another  calendar  month,  in which case the date for  payment  thereof
shall  be the  next  preceding  Euro-Dollar  Business  Day.  If the date for any
payment of  principal is extended by  operation  of law or  otherwise,  interest
thereon shall be payable for such extended time.

     (b) Unless the  Administrative  Agent shall have  received  notice from the
Borrower  prior to the date on which any  payment is due to the Banks  hereunder
that the Borrower will not make such payment in full, the  Administrative  Agent
may assume that the Borrower has made such payment in full to the Administrative
Agent on such date and the  Administrative  Agent  may,  in  reliance  upon such
assumption,  cause to be  distributed  to each  Bank on such due date an  amount
equal to the amount then due such Bank.  If and to the extent that the  Borrower
shall not have so made such payment, each Bank shall repay to the Administrative
Agent  forthwith on demand such amount  distributed  to such Bank  together with
interest thereon,  for each day from the date such amount is distributed to such
Bank until the date such Bank repays such amount to the Administrative Agent, at
the Federal Funds Rate.

     SECTION  2.12.  Funding  Losses.  If the  Borrower  makes  any  payment  of
principal  with  respect  to any  Euro-Dollar  Loan or any  Euro-Dollar  Loan is
converted (pursuant to Article 2, 6 or 8 or otherwise) on any day other than the
last  day of an  Interest  Period  applicable  thereto,  or the  last  day of an
applicable period fixed pursuant to Section 2.05(c), or if the Borrower fails to
borrow or prepay any  Euro-Dollar  Loans after notice has been given to any Bank
in accordance with Section  2.02(a),  2.09 or 2.10, the Borrower shall reimburse
each Bank within 15 days after demand for any resulting loss or expense incurred
by it (or by an  existing  or  prospective  Participant  in the  related  Loan),
including  (without  limitation) any loss incurred in obtaining,  liquidating or
employing  deposits from third  parties,  but  excluding  loss of margin for the
period  after any such  payment  or  conversion  or failure to borrow or prepay,
provided that such Bank shall have delivered to the Borrower a certificate as to
the amount of such loss or expense, which certificate shall be conclusive in the
absence of manifest error.

     SECTION 2.13. Computation of Interest and Fees. Interest based on the Prime
Rate and commitment  fees hereunder  shall be computed on the basis of a year of
365 days (or 366 days in a leap  year)  and paid for the  actual  number of days
elapsed (including the first day but excluding the last day). All other interest
shall be  computed  on the  basis of a year of 360 days and paid for the  actual
number of days elapsed (including the first day but excluding the last day).




                                       30





                                    ARTICLE 3
                                   CONDITIONS

     SECTION 3.01. Closing.  The closing hereunder shall occur upon satisfaction
of the following conditions:

     (a) the  Documentation  Agent shall have received all of the following,  in
form and substance  satisfactory  to the  Documentation  Agent and in sufficient
copies for each Bank:

               (i) duly executed  Notes for the account of each Bank dated on or
               before the Closing Date  complying with the provisions of Section
               2.03;

               (ii) the articles or certificate of  incorporation of each of the
               Borrower, the Parent Guarantor,  the Borrower's  Subsidiaries and
               the  Shareholder  Guarantors  (other  than Baron  Capital)  as in
               effect on the Closing  Date,  certified by the Secretary of State
               or equivalent  official of the  jurisdiction of  incorporation of
               such Person as of a recent date and by the Secretary or Assistant
               Secretary of such Person as of the Closing  Date,  and the bylaws
               of such Person as in effect on the Closing Date, certified by the
               Secretary or Assistant Secretary of such Person as of the Closing
               Date;

               (iii) a good  standing  certificate  for each of the Borrower and
               the Parent  Guarantor from the Secretary of State of its state of
               incorporation  and each state where the  Borrower is qualified to
               do  business  as a  foreign  corporation  as  of a  recent  date,
               together  with a  bring-down  certificate  by telex or  telecopy,
               dated the Closing Date;

               (iv) copies of the  resolutions  of the board of directors of (x)
               the Borrower  approving and authorizing  the execution,  delivery
               and  performance  by the Borrower of this Agreement and the other
               Loan  Documents  to  be  delivered  by  it  and  authorizing  the
               borrowing  of the Loans,  certified as of the Closing Date by the
               Secretary or an Assistant Secretary of the Borrower, and (y) each
               of the Parent  Guarantor,  the  Borrower's  Subsidiaries  and the
               Shareholder  Guarantors (other than Baron Capital)  approving and
               authorizing  the  execution,  delivery  and  performance  by such
               Person of all Loan Documents to be delivered by it,  certified as
               of the Closing Date by the Secretary or an Assistant Secretary of
               such Person;

               (v) a certificate  of the Secretary or an Assistant  Secretary of
               each  of  the  Borrower,  the  Parent  Guarantor,   each  of  the




                                               31




               Borrower's  Subsidiaries  and each  Shareholder  Guarantor (other
               than Baron Capital)  certifying the names and true  signatures of
               its  officers  authorized  to execute,  deliver and  perform,  as
               applicable, all Loan Documents to be delivered by it hereunder;

               (vi) a certificate signed by a Responsible Officer of each of the
               Borrower and the Parent Guarantor,  dated as of the Closing Date,
               stating that each of the conditions set forth in Sections 3.01(b)
               through (e) is satisfied as of such date;

               (vii) a Subsidiary  Guaranty  executed by each  Subsidiary of the
               Borrower;

               (viii) written advice relating to such Lien and judgment searches
               as either Agent shall have requested of the Parent  Guarantor and
               the Borrower,  and such termination statements or other documents
               as may be  necessary  to  release  any Lien in favor of any third
               party not otherwise permitted by Section 5.15;

               (ix) an opinion of (w) Randy S.  Segal,  counsel to the  Borrower
               and the Parent Guarantor,  substantially in the form of Exhibit B
               hereto, (x) counsel reasonably satisfactory to the Agents to each
               Shareholder Guarantor,  in form and substance satisfactory to the
               Documentation  Agent,  and (y)  Davis  Polk &  Wardwell,  special
               counsel  to the  Agents,  substantially  in the form of Exhibit C
               hereto;

               (x) a copy of the financial  statements  of the Parent  Guarantor
               referred  to  in  Section   4.10(a)  and  (b),   certified  by  a
               Responsible Officer of the Parent Guarantor;

               (xi) a Shareholder  Guaranty  duly  executed by each  Shareholder
               Guarantor,  the Baron  Capital  Letter of Credit  and the  Escrow
               Letter; and

               (xii)  all  documents  the  Documentation  Agent  may  reasonably
               request  relating to the  existence of the  Borrower,  any of the
               Borrower's Subsidiaries,  the Parent Guarantor or any Shareholder
               Guarantor,  the corporate  authority for and the validity of this
               Agreement, the Notes or the Shareholder Guaranties, and any other
               matters relevant hereto,  all in form and substance  satisfactory
               to the Documentation Agent;

     (b) all costs,  accrued and unpaid fees and  expenses  (including,  without
limitation,  participation  fees and legal fees and expenses) to the extent then
due and payable on the Closing  Date by the Borrower  hereunder  shall have been
paid;


                                       32






     (c) the Borrower and the Parent Guarantor shall have received proceeds (net
of fees and interest  reserves) of not less than  $140,000,000 from the issuance
of the Senior Notes, all conditions to the Acquisition (including receipt of any
approvals of the FCC) shall have been satisfied and the  Acquisition  shall have
been consummated;

     (d) the Hughes Bridge Loan  Agreement  shall have been  terminated  and all
amounts payable thereunder shall have paid in full; and

     (e) the  Existing  Credit  Facilities  shall have been  terminated  and all
amounts payable thereunder shall have been paid in full.

The Documentation  Agent shall promptly notify the Borrower and the Banks of the
Closing  Date,  and such notice shall be  conclusive  and binding on all parties
hereto.

     SECTION 3.02. Borrowings.  The obligation of any Bank to make a Loan on the
occasion  of any  Borrowing  is subject  to the  satisfaction  of the  following
conditions:

     (a) the fact that the Closing Date shall have occurred on or prior to March
31, 1998;

     (b)  receipt  by the  Administrative  Agent of a  Notice  of  Borrowing  as
required by Section 2.02(a);

     (c)  the  fact  that,  immediately  after  any  Borrowing,   the  aggregate
outstanding  principal  amount of the Loans will not exceed the aggregate amount
of the Commitments;

     (d) the fact that, immediately before and after such Borrowing,  no Default
shall have occurred and be continuing; and

     (e) the fact that the  representations  and  warranties of the Borrower and
the Parent Guarantor  contained in the Loan Documents shall be true on and as of
the date of such Borrowing.

Each Borrowing  hereunder shall be deemed to be a representation and warranty by
the  Borrower and the Parent  Guarantor on the date of such  Borrowing as to the
facts specified in clauses (b) through (e) of this Section.



                                       33





                                    ARTICLE 4
                         REPRESENTATIONS AND WARRANTIES

     Each of the Borrower and the Parent  Guarantor  represents and warrants (in
each case after  giving  effect to the  Acquisition;  provided  that for periods
prior to the Effective Date, the  representations and warranties with respect to
ARDIS are made to the  Borrower's and the Parent  Guarantor's  best knowledge in
reliance on the  representations and warranties in the ARDIS Purchase Agreement)
that,  except as set forth in the  section (if any) of the  Disclosure  Schedule
corresponding to the Section heading below:

     SECTION 4.01.  Corporate Existence and Power. Each of the Parent Guarantor,
the  Borrower,   and  each  of  its  Principal  Subsidiaries  and  Subsidiaries,
respectively,  (a) is a corporation duly  incorporated,  validly existing and in
good standing under the laws of the jurisdiction of its  incorporation;  (b) has
the power and authority and all material governmental licenses,  authorizations,
consents and approvals  required to carry on its business as now conducted;  (c)
is duly qualified as a foreign corporation,  licensed and in good standing under
the  laws of each  jurisdiction  where  its  ownership,  lease or  operation  of
property or the conduct of its business requires such qualification;  and (d) is
in compliance with all  Requirements  of Law except,  in the case of clauses (c)
and (d),  where  the  failure  to be so  qualified  or in  compliance  could not
reasonably be expected to have a Material Adverse Effect.

     SECTION 4.02.  Corporate  Authorization;  No Contravention.  The execution,
delivery and performance by each of the Parent Guarantor and its Subsidiaries of
any Loan  Document  to which it is a party  have  been  duly  authorized  by all
necessary  corporate action and do not and will not: (a) contravene the terms of
such  Person's  certificate  of  incorporation,  bylaws  or  other  organization
document;  (b) conflict with or result in any breach or contravention of, or the
creation  of any  Lien  under,  any  indenture,  agreement,  lease,  instrument,
Contractual Obligation,  injunction,  order, decree or undertaking to which such
Person is a party; or (c) violate any Requirement of Law.

     SECTION  4.03.  Government  Approvals.  All material  Government  Approvals
heretofore required to be obtained have been duly obtained, were validly issued,
are in full force and effect, are not subject to appeal and are held in the name
of, or for the  benefit  of, the  appropriate  Persons.  There is no  proceeding
pending  or, to the best  knowledge  of the  Borrower  or the Parent  Guarantor,
threatened  against  the Parent  Guarantor  or any of its  Subsidiaries,  or any
property of the Parent Guarantor or any of its Subsidiaries, which seeks, or may
reasonably be expected,  to rescind,  terminate,  materially adversely modify or
suspend any of the FCC  Licenses.  There has not  occurred  any event that would



                                       34




make unlikely the delivery or issuance as anticipated of, and when and as needed
all such Government  Approvals.  No such Government Approval already obtained is
subject to any restriction,  condition, limitation or other provision that would
have a Material  Adverse Effect.  The information set forth in each  application
submitted  by the Parent  Guarantor,  the  Borrower  or any of their  respective
Subsidiaries in connection  with each such  Government  Approval is accurate and
complete in all material  respects  taken as a whole,  except for  statements or
omissions  which  could not  reasonably  be  expected  to affect  adversely  the
validity of such Government  Approvals.  No other material consent,  approval or
authorization of, or declaration or filing with, any other Person is required in
connection with the execution, delivery, performance, validity or enforceability
of this Agreement or any other Loan Document.

     SECTION 4.04.  Binding Effect.  This Agreement and each other Loan Document
to which the Parent  Guarantor or any of its  Subsidiaries is a party constitute
the legal,  valid and binding  obligations of such Person,  enforceable  against
such Person in accordance with their respective terms,  except as enforceability
may be limited by applicable bankruptcy,  insolvency,  or similar laws affecting
the  enforcement  of  creditors'  rights  generally or by  equitable  principles
relating to enforceability.

     SECTION 4.05.  Litigation.  Except for matters  arising after the Effective
Date which could not reasonably be expected to have a Material  Adverse  Effect,
there are no actions, suits, proceedings,  claims or disputes pending, or to the
best  knowledge  of  the  Parent  Guarantor  or  the  Borrower,   threatened  or
contemplated  at law,  in equity,  in  arbitration  or before  any  Governmental
Authority,  against the Parent  Guarantor or any of its  Subsidiaries  or any of
their  respective  properties  which:  (a)  purport to affect or pertain to this
Agreement, or any Loan Document, or any of the transactions  contemplated hereby
or thereby; or (b) if determined adversely to the Parent Guarantor or any of its
Subsidiaries,  could  have a  Material  Adverse  Effect.  No  injunction,  writ,
temporary  restraining  order or any order of any nature has been  issued by any
court or other  Governmental  Authority  purporting  to enjoin or  restrain  the
execution,  delivery  and  performance  of  this  Agreement  or any  other  Loan
Document,  or directing that the transactions provided for herein or therein not
be consummated as herein or therein provided.

     SECTION  4.06. No Default.  No Default or Event of Default  exists or would
result from the incurring of Obligations  by the Parent  Guarantor or any of its
Subsidiaries  under any Loan Document.  Neither the Parent  Guarantor nor any of
its  Subsidiaries  is in  default  under  or  with  respect  to any  Contractual
Obligation  in any  respect  which,  individually  or  together  with  all  such
defaults, could have a Material Adverse Effect.


                                       35





     SECTION 4.07. ERISA Compliance. (a) Section 4.07 of the Disclosure Schedule
lists all Plans  maintained or sponsored by the Parent Guarantor or the Borrower
or to which either of them is obligated to contribute, and separately identifies
Plans  intended  to be  Qualified  Plans and  Multiemployer  Plans.  All written
descriptions  thereof  provided  to the  Agents  are  true and  complete  in all
material respects.  Each Plan is in compliance in all material respects with the
applicable  provisions  of  ERISA,  the Code and  other  Federal  or state  law,
including all requirements under the Code or ERISA for filing reports (which are
true and correct in all material  respects as of the date  filed),  and benefits
have been paid in accordance  with the  provisions of the Plan.  Each  Qualified
Plan has been  determined  by the IRS to qualify  under Section 401 of the Code,
and to the best knowledge of the Parent  Guarantor and the Borrower  nothing has
occurred which would cause the loss of such qualification.

     (b) There is no outstanding  liability under Title IV of ERISA with respect
to any Plan maintained or sponsored by any member of the Controlled Group (as to
which the  Parent  Guarantor  or the  Borrower  is or may be  liable),  nor with
respect to any Plan to which any member of the Controlled  Group  contributes or
is obligated to contribute  (wherein the Parent  Guarantor or the Borrower is or
may be liable).  No Plan maintained or sponsored by the Parent  Guarantor or the
Borrower provides medical or other welfare benefits or extends coverage relating
to such benefits  beyond the date of a  participant's  termination of employment
with the Parent Guarantor or Borrower,  except to the extent required by Section
4980B of the Code and at the sole expense of the  participant or the beneficiary
of the participant to the fullest extent  permissible  under such Section of the
Code. Each of the Parent Guarantor and the Borrower has complied in all material
respects with the notice and continuation coverage requirements of Section 4980B
of the Code.

     (c) No ERISA  Event has  occurred or is  reasonably  expected to occur with
respect to any Plan  maintained  or  sponsored  by the Parent  Guarantor  or the
Borrower  or to which the Parent  Guarantor  or the  Borrower  is  obligated  to
contribute.  There  are no  pending  or,  to the best  knowledge  of the  Parent
Guarantor and the Borrower,  threatened claims, actions or lawsuits,  other than
routine  claims for  benefits  in the usual and  ordinary  course,  asserted  or
instituted  against (i) any Plan maintained or sponsored by the Parent Guarantor
or the  Borrower or its  assets,  (ii) any member of the  Controlled  Group with
respect to any Qualified Plan of the Parent Guarantor or the Borrower,  or (iii)
any  fiduciary  with  respect to any Plan for which the Parent  Guarantor or the
Borrower  may  be  directly  or  indirectly  liable,   through   indemnification
obligations  or  otherwise.  Neither the Parent  Guarantor  nor the Borrower has
incurred  or  reasonably  expects to incur (i) any  liability  (and no event has
occurred  which,  with the giving of notice under  Section 4219 of ERISA,  would



                                       36




result  in such  liability)  under  Section  4201 of  ERISA  with  respect  to a
Multiemployer  Plan or (ii) any  liability  under Title IV of ERISA  (other than
premiums due and not  delinquent  under Section 4007 of ERISA) with respect to a
Plan. Neither the Parent Guarantor nor the Borrower has transferred any Unfunded
Pension  Liability  outside of the  Controlled  Group or otherwise  engaged in a
transaction that could be subject to Section 4069 or 4212(c) of ERISA.

     (d) Neither the Parent Guarantor nor the Borrower has engaged,  directly or
indirectly,  in a non-exempt prohibited  transaction (as defined in Section 4975
of the  Code or  Section  406 of  ERISA)  in  connection  with any  Plan,  which
transaction could have a Material Adverse Effect.

     SECTION  4.08.  Title to  Property.  Each of the Parent  Guarantor  and its
Principal Subsidiaries and the Borrower and its Subsidiaries has good record and
marketable  title in fee  simple  to or valid  leasehold  interests  in all real
property  used in its  business,  except for such defects in title as could not,
individually  or in the aggregate,  have a Material  Adverse  Effect.  Such real
property  is free and clear of all Liens or rights of others,  except  Permitted
Liens.

     SECTION  4.09.  Taxes.  Each of the  Parent  Guarantor  and  its  Principal
Subsidiaries  and the Borrower and its  Subsidiaries  have filed all Federal and
other  material  tax returns and reports  required to be filed and have paid all
Federal  and other  material  taxes,  assessments,  fees and other  governmental
charges  levied  or  imposed  upon  them or their  properties,  income or assets
otherwise due and payable  except those which are being  contested in good faith
by appropriate proceedings and for which adequate reserves have been provided in
accordance with GAAP and no Notice of Lien has been filed or recorded.  There is
no  proposed  tax  assessment  against  the  Parent  Guarantor  or  any  of  its
Subsidiaries  which would, if the assessment were made, have a Material  Adverse
Effect.

     SECTION 4.10. Financial Condition.

     (a) The audited consolidated statements of financial position of the Parent
Guarantor  and its  Subsidiaries  dated  December  31,  1996,  and  the  related
consolidated  statements  of loss,  stockholders'  equity and cash flows for the
fiscal  year ended on that  date:  (i) were  prepared  in  accordance  with GAAP
consistently applied throughout the periods covered thereby, except as otherwise
expressly noted therein,  (ii) fairly  present,  in all material  respects,  the
financial  condition of the Parent Guarantor and its Subsidiaries as of the date
thereof and results of operations for the period covered  thereby and (iii) show
all material  Indebtedness and other liabilities,  direct or contingent,  of the
Parent  Guarantor  and its  consolidated  Subsidiaries  as of the  date  thereof
(including liabilities for taxes and material commitments).



                                       37






     (b) The unaudited pro forma summary consolidated condensed balance sheet of
the Parent Guarantor and its Subsidiaries as of September 30, 1997 together with
the related pro forma summary  condensed  statement of  operations  data for the
nine months then ended  fairly  present,  in  conformity  with GAAP applied on a
basis  consistent  with the financial  statements  referred to in subsection (a)
above,  the  consolidated  financial  position of the Parent  Guarantor  and its
Subsidiaries as of such date, based on the assumptions set forth therein.  As of
such date and the Closing Date, the Parent  Guarantor and its  Subsidiaries  had
and  have no  material  liabilities,  contingent  or  otherwise,  which  are not
properly  reflected on such balance sheet  (including  liabilities for taxes and
material commitments).

     (c) Since September 30, 1997, there has been no Material Adverse Effect.

     SECTION 4.11. Environmental Matters. The operations of the Parent Guarantor
and  each  of  its  Subsidiaries  comply  in  all  material  respects  with  all
Environmental  Laws.  The Parent  Guarantor  and each of its  Subsidiaries  have
obtained all licenses, permits,  authorizations and registrations required under
any Environmental Law ("Environmental  Permits") necessary for its operations to
comply  in  all  material  respects  with  Environmental   Laws,  and  all  such
Environmental Permits are in full force and effect, and the Parent Guarantor and
each  of  its  Subsidiaries  are in  material  compliance  with  all  terms  and
conditions of such Environmental  Permits. None of the Parent Guarantor,  any of
its  Subsidiaries  or any of their  present or, to the  knowledge  of the Parent
Guarantor  and the  Borrower,  past  property  or  operations  is subject to any
outstanding  written order from or agreement with any Governmental  Authority or
other  Person,  nor  subject  to  any  judicial  or  administrative  proceeding,
respecting any Environmental  Law,  Environmental  Claim or Hazardous  Material.
There  are  no  conditions  or   circumstances   which  may  give  rise  to  any
Environmental  Claim arising from the operations of the Parent  Guarantor or its
Subsidiaries,  including  Environmental Claims associated with any operations of
the Parent Guarantor or its Subsidiaries,  with a potential  liability in excess
of  $5,000,000  in  the  aggregate.  Without  limiting  the  generality  of  the
foregoing,  the Parent Guarantor and its Subsidiaries  have met all notification
requirements under Title III of the Superfund Amendments and Reauthorization Act
of 1986 or any other Environmental Law.

     SECTION 4.12. Regulated Entities. None of the Parent Guarantor,  any Person
controlling  the  Parent  Guarantor,  or  any  Subsidiary  thereof,  is  (a)  an
"Investment  Company" within the meaning of the Investment  Company Act of 1940;




                                       38




or (b) subject to regulation  under the Public  Utility  Holding  Company Act of
1935,  the Federal  Power Act,  the  Interstate  Commerce  Act, any state public
utilities code or any other Federal or state statute or regulation  limiting its
ability to incur Indebtedness.

     SECTION 4.13.  Subsidiaries.  As of the Closing Date, the Borrower does not
have any Subsidiaries and has no equity  investments in any other corporation or
entity.

     SECTION  4.14.   Insurance.   The   properties  of  the  Borrower  and  its
Subsidiaries  are  insured  with  financially  sound  and  reputable   insurance
companies,  in such amounts, with such deductibles and covering such risks as is
customarily  carried on by companies  engaged in similar  businesses  and owning
similar properties in localities where the Borrower or such Subsidiary operates.

     SECTION  4.15.  Business.  The  Borrower  and  its  Subsidiaries  have  not
conducted  any business  other than as  described  in the  Offering  Memorandum.
Neither the business nor the properties of the Borrower and its Subsidiaries are
or have been affected by any fire, explosion, accident, strike, lockout or other
labor dispute,  drought, storm, hail, earthquake,  embargo, act of God or of the
public enemy or other casualty  (whether or not covered by insurance)  which has
had a Material Adverse Effect.

     SECTION 4.16. Disclosure.  The information (including,  without limitation,
the information in the Offering Memorandum)  furnished in writing at or prior to
the Closing Date by the Parent Guarantor or the Borrower to any Agent or Bank in
connection with this Agreement and the transactions contemplated hereby is true,
complete and accurate in every material respect or based on reasonable estimates
on the date as of which  such  information  is  stated or  certified  and is not
incomplete  by  omitting  to state  any  material  fact  necessary  to make such
information  (taken as a whole)  not  misleading  in light of the  circumstances
under  which such  information  was made.  The pro forma  financial  projections
contained in the Offering Memorandum were made in good faith and the assumptions
on the basis of which such projections were made were (when made) and are (as of
the date of this  Agreement)  reasonable.  There is no fact  known to the Parent
Guarantor  or the  Borrower  on the date as of  which  this  representation  and
warranty is made that has not been disclosed in writing to the Agent which could
reasonably be expected to have a Material Adverse Effect.



                                       39





                                    ARTICLE 5
                                    COVENANTS

     Each of the Borrower and the Parent  Guarantor  agrees that, so long as any
Bank has any Commitment  hereunder or any amount payable  hereunder or under any
Note remains unpaid:

     SECTION 5.01. Information. The Borrower will deliver to each of the Banks:

     (a) as soon as available,  but not later than 90 days after the end of each
fiscal year of the Borrower and the Parent Guarantor,  respectively,  commencing
with  the  fiscal  year  ending  December  31,  1997,  a  copy  of  the  audited
consolidated  balance sheets of the Borrower and the Parent  Guarantor as at the
end of such year and the  related  audited  consolidated  statements  of income,
stockholders'  equity and cash flows for such fiscal year, setting forth in each
case in comparative  form the figures for the previous year, and  accompanied by
the opinion of Arthur Andersen LLP or another nationally-recognized  independent
public accounting firm which report shall state that such consolidated financial
statements  present fairly, in all material  respects,  the financial  position,
results of  operations  and cash flows for the periods  indicated in  conformity
with GAAP applied on a basis consistent with prior years;

     (b) as soon as available,  but not later than 45 days after the end of each
of the first three fiscal quarters of each year,  commencing with the first such
fiscal  quarter  to end  after  the  Effective  Date,  a copy  of the  unaudited
consolidated  balance sheets of the Borrower and Parent  Guarantor as of the end
of such quarter and the related consolidated statements of income, stockholders'
equity and cash flows for the period  commencing  on the first day and ending on
the  last day of such  quarter,  and  certified  by an  appropriate  Responsible
Officer as fairly presenting,  in all material respects, in accordance with GAAP
(except for the absence of footnote disclosure),  the financial position and the
results of operations of the Borrower and the Parent Guarantor; and

     (c) as soon as  available,  any other interim  financial  statements of the
Borrower and its Subsidiaries  reasonably  requested by the Administrative Agent
at the direction of the Required Banks.

     SECTION 5.02. Certificates; Other Information. The Borrower will deliver to
each of the Banks:

     (a) concurrently with the delivery of the financial  statements referred to
in Section  5.01(a)  above, a certificate of the  independent  certified  public


                                       40





accountants  reporting on such financial  statements  stating that in making the
examination necessary therefor no knowledge was obtained of any Default or Event
of Default, except as specified in such certificate;

     (b) concurrently with the delivery of the financial  statements referred to
in Section 5.01(a) above, a certificate of a Responsible Officer of the Borrower
(i) stating that, to the best of such officer's knowledge, the Borrower,  during
such  period,  has  observed  or  performed  all  of  its  covenants  and  other
agreements,  and satisfied  every  condition  contained in this  Agreement to be
observed,  performed  or  satisfied by it, and that such officer has obtained no
knowledge  of any  Default  or Event of  Default  except  as  specified  in such
certificate, (ii) when applicable, showing in detail the calculations supporting
such  statement in respect of Article 5 and (iii)  setting forth the Excess Cash
Flow for such  period,  together  with the  calculation  thereof  in  reasonable
detail;

     (c)  promptly  after  the same are  filed,  copies  of (if,  in the case of
reports to the FCC,  such reports are material)  all  financial  statements  and
regular,  periodical or special reports which the Borrower, the Parent Guarantor
or any  Subsidiary  of the  Parent  Guarantor  may make to,  or file  with,  the
Securities  and  Exchange  Commission,  the  FCC or  any  successor  or  similar
Governmental Authorities; and

     (d)  promptly,  such  additional  financial  and other  information  as the
Administrative  Agent,  at the  request  of any  Bank,  may  from  time  to time
reasonably request.

     SECTION 5.03.  Notices.  The Borrower shall promptly  notify the Agents and
each Bank of:

     (a)  the  occurrence  of  any  Default  or  Event  of  Default,  and of the
occurrence or existence of any event or  circumstance  that could  reasonably be
expected to become a Default or Event of Default;

     (b)  any (i)  breach  or  non-performance  of,  or any  default  under  any
Contractual  Obligation  which  could  reasonably  be  expected  to  result in a
Material Adverse Effect; or (ii) dispute, litigation, investigation,  proceeding
or suspension which may exist at any time between the Parent Guarantor or any of
its  Subsidiaries  and any  Governmental  Authority  and  which,  if  determined
adversely to the Parent Guarantor or any of its  Subsidiaries,  could reasonably
be expected to result in a Material Adverse Effect;

     (c) the commencement of, or any material  development in, any litigation or
proceeding  affecting the Parent  Guarantor or any  Subsidiary  (i) in which the
amount of  damages claimed is  $5,000,000 (or its equivalent in another currency

                                       41






or currencies) or more, (ii) in which injunctive or similar relief is sought and
which, if adversely  determined,  could have a Material Adverse Effect, or (iii)
in which the relief sought is an injunction or other stay of the  performance of
any Loan  Document  or the  operations  of the  Parent  Guarantor  or any of its
Subsidiaries;

     (d) upon, but in no event later than ten days after,  becoming aware of (i)
any and all enforcement,  cleanup,  removal or other  governmental or regulatory
actions instituted,  completed or threatened against the Parent Guarantor or any
Subsidiary or any of their properties  pursuant to any applicable  Environmental
Laws, (ii) all other Environmental  Claims or (iii) any environmental or similar
condition on any real  property  adjoining or in the vicinity of the property of
the  Parent  Guarantor  or any of its  Subsidiaries  that  could  reasonably  be
anticipated  to cause  such  property  or any part  thereof to be subject to any
restrictions  on the  ownership,  occupancy,  transferability  or  use  of  such
property under any Environmental Laws;

     (e) any other  litigation or proceeding  affecting the Parent  Guarantor or
any of its  Subsidiaries  which the Parent Guarantor would be required to report
to the Securities and Exchange  Commission  pursuant to the Securities  Exchange
Act of 1934,  within four days after  reporting the same to the  Securities  and
Exchange Commission;

     (f) any ERISA Event  affecting the Borrower or any member of its Controlled
Group (but in no event more than ten days after such ERISA Event)  together with
(i) a copy of any notice  with  respect to such ERISA  Event filed with the PBGC
and (ii) any notice  delivered  by the PBGC to the Borrower or any member or its
Controlled Group with respect to such ERISA Event;

     (g) any Material  Adverse Effect  subsequent to the date of the most recent
audited financial  statements of the Borrower delivered to the Banks pursuant to
Section 5.01(a);

     (h) any  material  change in  accounting  policies or  financial  reporting
practices;

     (i) any labor  controversy  resulting  in or  threatening  to result in any
strike,  work stoppage,  boycott,  shutdown or other labor disruption against or
involving the Borrower or any Subsidiary;

     (j) any material revision of the Borrower's business plan;

     (k) the adoption of each capital expenditures budget by the Borrower;


                                       42





     (l) any event  that  could  reasonably  be  expected  to result in Net Cash
Proceeds requiring a mandatory prepayment pursuant to Section 2.09; and

     (m) the  delivery  of, or  receipt  of, any  notice of (i) a  reduction  in
coverage of any insurance required to be maintained by Section 5.06 or otherwise
procured by the Borrower covering loss or damage to any material property of the
Borrower (other than a reduction in coverage or amount  resulting from a payment
thereunder)  or (ii) the  cancellation  or  non-renewal  of any  such  insurance
policy.

Each  notice  pursuant  to this  Section  shall be  delivered  promptly  after a
Responsible Officer becomes aware of the subject matter of such notice and shall
be accompanied by a written  statement by a Responsible  Officer of the Borrower
setting forth details and effective date of the  occurrence  referred to therein
and stating what action the Borrower proposes to take with respect thereto.

     SECTION 5.04.  Conduct of Business;  Preservation  of Corporate  Existence.
Each of the Parent Guarantor and the Borrower shall, and shall cause each of its
Principal Subsidiaries and Subsidiaries, respectively: (a) to engage in business
of the same  general  type as now  conducted  by the  Parent  Guarantor  and its
Subsidiaries  (including  ARDIS  and  AMRC  Holdings  and  Subsidiaries  of AMRC
Holdings);  (b) to preserve and maintain in full force and effect its  corporate
existence  and good  standing  under  the laws of its State or  jurisdiction  of
incorporation; (c) to preserve and maintain in full force and effect all rights,
privileges,  qualifications,  permits,  licenses  and  franchises  necessary  or
desirable  in the normal  conduct  of its  business;  (d) to use its  reasonable
efforts,  in the ordinary course and consistent with past practice,  to preserve
its  business  organization  and  preserve  the  goodwill  and  business  of the
customers,  suppliers and others having  business  relations with it; and (e) to
preserve  or renew all of its  registered  trademarks,  trade  names and service
marks, the non-preservation of which could have a Material Adverse Effect.

     SECTION 5.05. Maintenance of Property.  Each of the Borrower and the Parent
Guarantor shall maintain, and shall cause each of its Principal Subsidiaries and
Subsidiaries,  respectively, to maintain, and preserve all its property which is
used or useful in its business in good  working  order and  condition,  ordinary
wear and tear excepted.

     SECTION 5.06.  Maintenance of Insurance.  (a) The Borrower shall procure at
its own expense and  maintain in full force and effect at all times on and after
the Effective Date with responsible  insurance  carriers with a Best's rating of



                                       43




A/VII or better  (except  for  policies  underwritten  by  Lloyds of London  and
companies  acceptable  to the  Agents and the  Required  Banks),  the  following
insurance:

                    (i) Workers' Compensation Insurance:  Except as to exposures
                    in those  jurisdictions in which the state government is the
                    sole source of such  insurance,  as  required by  applicable
                    state  laws  including,   without   limitation,   employer's
                    liability insurance with the following limits: bodily injury
                    by  accident:  $100,000  each  accident;  bodily  injury  by
                    disease:  $100,000  each  employee;  and  bodily  injury  by
                    disease: $500,000 policy limit (the policies with respect to
                    which shall include an all states' endorsement).

                    (ii)  Commercial  General  Liability:   Against  claims  for
                    personal  injury  (including  bodily  injury  and death) and
                    property damage in such amounts as are  customarily  carried
                    by companies of established  repute engaged in the same or a
                    similar  business  but  not  to  exceed  $5,000,000  in  the
                    aggregate.   Such  insurance  shall  provide   coverage  for
                    products/completed    operations,    blanket    contractual,
                    explosion,  collapse and  underground  coverage,  broad form
                    property   damage  and  personal   injury   insurance   with
                    $1,000,000 each  occurrence,  $1,000,000  general  aggregate
                    (other  than  products/completed   operations),   $1,000,000
                    personal   and    advertising    limit,    and    $1,000,000
                    products/completed operations aggregate limit.

                    (iii)  Business  Automobile  Liability:  Against  claims for
                    personal  injury  (including  bodily  injury  and death) and
                    property  damage covering all owned,  leased,  non-owned and
                    hired motor  vehicles (to the extent there are any thereof),
                    with a $2,000,000  minimum limit per occurrence for combined
                    bodily injury and property damage and in the aggregate where
                    applicable.

                    (iv)  Business   Interruption   Insurance:   To  the  extent
                    reasonably  obtainable on customary terms and conditions and
                    with customary exclusions,  with respect to any risk of loss
                    in respect of which the  Borrower in its  judgment  does not
                    then have  adequate  redundant  or  replacement  property or
                    assets   available   which   would   prevent   any  loss  or
                    interruption  of  any  cash  flow  if  such  loss  occurred,
                    business  interruption  insurance with a $2,000,000  minimum
                    limit per occurrence.

                    (v) Property Damage Insurance: (x) Property damage insurance
                    on an  "all  risk"  basis  (with  customary  conditions  and
                    exclusions) including coverage against damage or loss caused
                    by earth  movement and flood and providing  coverage for its



                                       44




                    satellites and  communications  ground segment (the "Covered
                    Property"),  in a  minimum  aggregate  amount  equal  to the
                    lesser of (1) the  "full  insurable  value"  of the  Covered
                    Property and (2) 110% of all Obligations and (y) unless both
                    of the Agents shall otherwise agree, In-Orbit Insurance. For
                    purposes  of this  clause  (v) and  Section  5.06(b),  "full
                    insurable  value" shall mean the full  replacement  value of
                    the  Covered   Property,   including  any  improvements  and
                    equipment  and  supplies,  without  deduction  for  physical
                    depreciation and/or obsolescence; all such policies may have
                    deductibles of not greater than  $250,000,  except for earth
                    movement  insurance which will have the lowest deductible as
                    shall  (in  the  opinion  of the  Agents)  be  available  on
                    commercially reasonable terms in the insurance market place.
                    Such insurance shall include an "agreed amount" clause.  For
                    purposes of this clause (v), "In-Orbit Insurance" shall mean
                    in-orbit  insurance,  with insurance carriers  acceptable to
                    the  Agents,   in  a  minimum   aggregate  amount  equal  to
                    $184,000,000  and when the ACTEL Lease Agreement and the TMI
                    Purchase  Agreement become effective an additional amount of
                    in-orbit insurance of $50,000,000 shall be obtained to cover
                    MSAT-1  and  up  to  $50,000,000  of  such  $184,000,000  of
                    insurance  on MSAT-2 may be for the  account  and benefit of
                    ACTEL or other  lessee under a Satellite  Lease  Arrangement
                    (or if  coverage  in  such  amounts  is  unavailable  to the
                    Borrower  using its  reasonable  best  efforts,  such lesser
                    amounts  as the  Borrower  is able  to  obtain)  and  having
                    deductibles and other terms and conditions as are reasonably
                    available  in  the  market  at   reasonable   cost  and  are
                    acceptable to the Agents.

     (b) All  policies  of  insurance  required  to be  maintained  pursuant  to
Sections  5.06(a)(iv)  and  5.06(a)(v)  or  otherwise  procured by the  Borrower
covering loss or damage to any of the Borrower's property shall provide that (i)
there  shall be no  recourse  against  the  Agents or the Banks for  payment  of
premiums or other amounts with respect  thereto,  (ii) to the extent  available,
the insurer is required  to provide  the  Administrative  Agent with at least 30
days (or ten days, in the case of nonpayment of premiums)  prior written  notice
of reduction in coverage or amount (other than a reduction in coverage or amount
resulting from a payment thereunder),  cancellation or non-renewal of any policy
and (iii) the proceeds of all policies  (other than in respect of  comprehensive
general liability,  workers' compensation and comprehensive automobile liability
insurance)  shall be payable to the  Administrative  Agent  pursuant to standard
first mortgagee endorsement,  without contribution,  substantially equivalent to
the New York standard mortgagee  endorsement.  If the Borrower fails or may fail
to timely file any proof of loss, the Administrative  Agent shall have the right
to join the  Borrower in  submitting  a proof of any loss in excess of $250,000.
All such  policies  (other than in respect of workers'  compensation  insurance)
shall insure the interests of the Insured Parties, as their interest may appear,




                                       45




and shall  further  provide,  to the extent such  insurance  is  available  at a
commercially  reasonable rate, that payments shall be made thereunder regardless
of any breach or  violation  by the  Borrower  of  warranties,  declarations  or
conditions  not  contained  in such  policies,  any  action or  inaction  of the
Borrower  (other than  nonpayment  of  premiums) or others,  or any  foreclosure
relating to its satellite or communications ground segment or any other business
of the  Borrower or any change in  ownership of all or any portion of thereof or
any other  business of the  Borrower.  Each such policy  shall (i) except in the
case of insurance required to be maintained pursuant to Sections 5.06(a)(iv) and
5.06(a)(v),  waive  any  right of  subrogation  against  the  Banks  (and  their
respective officers, employees and agents), (ii) except in the case of insurance
required  to be  maintained  pursuant to Sections  5.06(a)(iv)  and  5.06(a)(v),
include a severability of interest or cross liability clause, (iii) provide that
the insurance be primary and not excess of or  contributory  to any insurance or
self-insurance maintained by the Borrower, the Agents or the Banks, (iv) contain
a breach of warranty  clause in favor of the Agents and the Banks and (v) except
in the case of workers'  compensation  insurance,  name the  Insured  Parties as
their interests may appear, as additional insureds or loss payees.

     (c) The Borrower shall deliver to the Administrative  Agent, within 30 days
after the close of each  fiscal  year,  commencing  with the fiscal  year ending
December  31,  1998,  a  certificate  of  International  Space  Brokers,   Inc.,
Metro/Risk,  Inc. or other recognized independent insurance brokers,  reasonably
acceptable to the Required  Banks,  (i) confirming  that all insurance  policies
required  pursuant to this Section 5.06 are in force on the date  thereof,  (ii)
confirming the names of the companies  issuing such policies,  (iii)  confirming
the  amounts  and  expiration  date or dates of such  policies,  (iv)  including
certificates  evidencing  such policies marked "premium paid" for the prior year
and (v) stating that in such  broker's  opinion  after due  investigation,  such
policies substantially comply with the requirements of this Section 5.06.

     (d) In the event the Borrower  fails to take out or  maintain,  or fails to
cause to be taken out or  maintained,  the full insurance  coverage  required by
this Section 5.06, the Administrative  Agent (upon the direction of the Required
Banks),  upon 30 days' prior notice (unless the  aforementioned  insurance would
lapse  within  such  period,  in which event  notice  should be given as soon as
reasonably  possible) to the Borrower of any such failure, may (but shall not be
obligated  to) take out the required  policies of insurance and pay the premiums
on the same. All amounts so advanced therefor by the Administrative  Agent shall
be immediately  reimbursed by the Borrower to the Administrative  Agent, and the
Borrower shall forthwith pay such amounts to the Administrative  Agent, together
with  interest  thereon at the sum of 2% plus the rate  otherwise  applicable to
Base Rate Loans for each day until paid.


                                       46






     (e) The  Administrative  Agent  shall  promptly  notify  each  Bank of each
written notice  received by it with respect to the  cancellation  of or material
adverse change in any insurance policy required to be maintained by the Borrower
pursuant to this Section 5.06.

     SECTION 5.07. Payment of Obligations.  Each of the Parent Guarantor and the
Borrower  shall,  and  shall  cause  each  of  its  Principal  Subsidiaries  and
Subsidiaries,  respectively,  to, pay and discharge as the same shall become due
and  payable,  all  its  obligations  and  liabilities,  including:  (a) all tax
liabilities,  assessments  and  governmental  charges  or levies  upon it or its
properties  or  assets,  unless  the same are being  contested  in good faith by
appropriate  proceedings and adequate reserves in accordance with GAAP are being
maintained by such Person; (b) all lawful claims which, if unpaid,  might by law
become a Lien upon its property  (excluding claims being contested in good faith
by the Borrower,  and for which adequate  reserves have been made or as to which
the corresponding liens have been bonded);  and (c) all Indebtedness as and when
due and payable but subject to any  subordination  provisions  contained  in any
instrument or agreement evidencing such Indebtedness.

     SECTION 5.08.  Compliance with Laws.  Each of the Parent  Guarantor and the
Borrower shall comply,  and shall cause each of its Principal  Subsidiaries  and
Subsidiaries,  respectively,  to  comply,  in all  material  respects  with  all
Requirements of Law of any Governmental Authority having jurisdiction over it or
its business (including the Federal Fair Labor Standards Act and ERISA),  except
such as may be  contested  in good faith or as to which a bona fide  dispute may
exist.

     SECTION  5.09.  Inspection  of Property and Books and Records.  Each of the
Parent  Guarantor and the Borrower shall  maintain,  and shall cause each of its
Principal Subsidiaries and Subsidiaries, respectively, to maintain, proper books
of record and account,  in which full,  true and correct  entries in  conformity
with GAAP consistently  applied shall be made of all financial  transactions and
matters  involving  the assets and  business  of the  Parent  Guarantor  and the
Borrower and such Principal  Subsidiaries.  Each of the Parent Guarantor and the
Borrower  will permit,  and will cause each of its  Principal  Subsidiaries  and
Subsidiaries,  respectively, to permit,  representatives of any Agent or Bank to
visit and inspect any of its properties, to examine its corporate, financial and
operating records and make copies thereof or abstracts therefrom, and to discuss
its affairs, finances and accounts with its directors,  officers,  employees and
independent  public  accountants at such reasonable times during normal business
hours and as often as may be reasonably desired,  upon reasonable advance notice
to the Parent Guarantor or the Borrower,  as the case may be; provided that when




                                       47




an Event of Default exists representatives from the United States offices of any
Agent  or Bank may  visit  and  inspect  at the  expense  of the  Borrower  such
properties at any time during  business hours and without  advance  notice.  The
Borrower shall reimburse the Agents and the Banks for their reasonable  expenses
incurred in  conducting  such visits and  examinations  when an Event of Default
exists.

     SECTION 5.10.  Environmental Laws. (a) Each of the Parent Guarantor and the
Borrower shall, and shall cause each of its respective  Subsidiaries to, conduct
its  operations  and keep and  maintain  its  property  in  compliance  with all
Environmental Laws.

     (b) Upon written  request of any Agent or Bank,  the Borrower  shall submit
and cause  each of its  Subsidiaries  to submit,  to such Agent or Bank,  at the
Borrower's sole cost and expense at reasonable intervals,  a report providing an
update of the  status  of and any  environmental,  health  or safety  compliance
obligation, remedial obligation or liability, that could, individually or in the
aggregate, result in liability in excess of $5,000,000.

     SECTION 5.11.  Use of Proceeds.  The Borrower shall use the proceeds of the
Loans only for general corporate  purposes,  including capital  expenditures and
the  refinancing of  obligations  under the Hughes Bridge Loan Agreement and the
Existing Credit  Facilities.  No portion of the Loans will be used,  directly or
indirectly,  for the purpose,  whether  immediate,  incidental  or ultimate,  of
buying or carrying any "margin  stock"  within the meaning of  Regulation  U. No
proceeds  of any Loans will be used to acquire any  security in any  transaction
which is subject to Section 13 or 14 of the Securities  Exchange Act of 1934, as
amended.

     SECTION 5.12. No Subsidiaries. The Borrower shall not have any Subsidiaries
or equity  investments in any other corporation or entity except as set forth on
Schedule 4.13.

     SECTION 5.13.  Government  Approvals.  The Borrower shall,  and shall cause
each of its Subsidiaries to, comply with the terms of and maintain in full force
and effect the FCC Licenses,  and all amendments  thereto,  and shall, and shall
cause each of its Subsidiaries to, obtain, maintain and comply with the terms of
all other  Government  Approvals which are necessary  under  applicable laws and
regulations in connection with the Borrower's or such Subsidiary's  business. No
such  Government  Approval  shall  be  subject  to any  restriction,  condition,
limitation or other provision that would have a Material Adverse Effect.

     SECTION  5.14.  Further  Assurances.  Each of the  Borrower  and the Parent
Guarantor  shall  ensure  that all  written  information,  exhibits  and reports



                                       48




furnished  to the Banks do not and will not  contain any untrue  statement  of a
material  fact and do not and will not omit to state  any  material  fact or any
fact necessary to make the statements  contained therein not misleading in light
of the circumstances in which made, and will promptly disclose to the Agents and
the Banks and correct any defect or error that may be  discovered  therein or in
any Loan Document or in the execution, acknowledgment or recordation thereof.

     SECTION  5.15.  Limitation on Liens.  Neither the Parent  Guarantor nor the
Borrower shall, nor shall either permit any member of the Parent Guarantor Group
to, directly or indirectly,  make, create,  incur, assume or suffer to exist any
Lien upon or with  respect to any part of its  property  or assets,  whether now
owned  or  hereafter  acquired,  or offer  or  agree  to do so,  other  than the
following ("Permitted Liens"):

     (a) any Lien existing on the Effective Date securing  Indebtedness existing
on the Effective Date and identified on Schedule 5.15;

     (b) any  Lien in  favor  of the  Administrative  Agent  created  under  the
Security and Pledge Agreement (as defined in the Term Credit  Agreement) and any
Lien  in  favor  of the  Shareholder  Guarantors  pursuant  to  the  Shareholder
Guarantor Security Agreement;

     (c) Liens for taxes, fees,  assessments or other governmental charges which
are not  delinquent or remain  payable  without  penalty,  or to the extent that
non-payment  thereof is permitted by Section  5.07,  provided  that no Notice of
Lien has been filed or recorded;

     (d)  carriers',  warehousemen's,   mechanics',  landlords',  materialmen's,
repairmen's  or other similar  Liens arising in the ordinary  course of business
which do not  secure  Indebtedness  and are not  delinquent  or  remain  payable
without penalty;

     (e) Liens  (other  than any Lien  imposed by ERISA) on the  property of any
member of the Parent Guarantor Group incurred,  or pledges or deposits required,
in connection  with  workmen's  compensation,  unemployment  insurance and other
social security legislation;

     (f) Liens on the  property  of any  member of the  Parent  Guarantor  Group
securing (i) the performance of bids,  trade contracts  (other than for borrowed
money), leases, statutory obligations, and (ii) obligations on surety and appeal
bonds,  and (iii) other  obligations  of a like nature  incurred in the ordinary
course of  business  which do not secure  Indebtedness,  provided  that all such
Liens in the aggregate could not cause a Material Adverse Effect;


                                       49






     (g) easements,  rights-of-way,  restrictions and other similar encumbrances
incurred in the ordinary  course of business  which,  in the aggregate,  are not
substantial in amount,  and which do not in any case materially detract from the
value of the property  subject thereto or interfere with the ordinary conduct of
the businesses of the Parent Guarantor Group;

     (h) Liens on any asset  which is the  subject of a capital  lease  securing
Indebtedness incurred or assumed for the purpose of financing all or any part of
the  cost of  acquiring  such  asset,  provided  that  (x)  such  Lien  attaches
concurrently with or within 30 days after the acquisition  thereof,  and (y) the
sum of the aggregate principal amount of such Indebtedness secured by such Liens
shall not exceed $15,000,000;

     (i) Liens on  contract  rights  under  subscriber  equipment  leases  sold,
pledged or  otherwise  transferred  pursuant to any bona fide  financing of such
leases;

     (j) Liens on property and assets of AMRC Holdings and its Subsidiaries; and

     (k) Liens to secure  Vendor  Financing  Indebtedness  permitted  by Section
5.23(k);  provided  that such Liens  cover only the  assets  acquired  with such
Vendor Financing Indebtedness.

     SECTION 5.16.  Disposition of Assets,  Consolidations and Mergers.  Neither
the Parent  Guarantor nor the Borrower shall,  nor shall it permit any member of
the Parent Guarantor Group to, directly or indirectly,  (i) sell, assign, lease,
convey,  transfer  or  otherwise  dispose  of  (whether  in one or a  series  of
transactions) any of its assets,  business or property  (including  accounts and
notes  receivable  (with  or  without  recourse)  and  equipment  sale-leaseback
transactions) or (ii) merge or consolidate with any other Person,  or enter into
any agreement to do any of the foregoing described in clauses (i) or (ii) except
for the following;  provided that immediately  after giving effect to any of the
following, no Default or Event of Default would exist:

     (a) sales, transfers, or other dispositions of inventory, or used, worn-out
or surplus  property,  or property of no further use to the Parent Guarantor and
its Subsidiaries, all in the ordinary course of business;

     (b) sales,  transfers,  or other  dispositions of equipment in the ordinary
course of business to the extent that such  equipment  is  exchanged  for credit




                                       50




against the purchase price of similar  replacement  equipment or the proceeds of
such  sale  are  reasonably  promptly  applied  to the  purchase  price  of such
replacement equipment;

     (c) sales,  transfers,  or other  dispositions of communications  services,
capacity or equipment pursuant to the customer contracts  providing for the sale
of  communications  services,  capacity or equipment  in the ordinary  course of
business;

     (d)  sales,   transfers  or  other  dispositions   pursuant  to  bona  fide
sale-leaseback  financings in which the lease gives rise solely to Capital Lease
Obligations;  provided,  however,  that  any  such  sales,  transfers  or  other
dispositions are not permitted with any assets of the communications network;

     (e)  sales,  transfers,  or other  dispositions  of assets in the  ordinary
course of business having a fair market value not exceeding $500,000 per item or
$1,000,000 in the aggregate in any fiscal year (excluding  sales,  transfers and
dispositions  theretofore  approved in accordance  with the terms hereof in such
fiscal year);

     (f) sales,  transfers or other  dispositions of assets to Sales Corporation
to be used in  connection  with the  sales  and  marketing  of  services  of the
Borrower  and  having  a fair  market  value  not  exceeding  $5,000,000  in the
aggregate during the term of this Agreement;

     (g)  sales,  transfers  or other  dispositions  of  contract  rights  under
subscriber equipment leases pursuant to any bona fide financing of such leases;

     (h) non-exclusive licenses of technology and other intangible assets;

     (i)  sales of mobile  earth  terminals  and  related  equipment,  and other
inventory;

     (j) any  Subsidiary of the Borrower may merge,  consolidate or combine with
or into, or transfer  assets to the Borrower or one or more  Subsidiaries of the
Borrower;  provided  that with  respect to any such  transaction  involving  the
Borrower,  the Borrower shall be the continuing or surviving  corporation and if
any  such  transaction   shall  be  between  a  Subsidiary  and  a  wholly-owned
Subsidiary,  the  wholly-owned  Subsidiary  shall be the continuing or surviving
corporation;

     (k) any Subsidiary of the Borrower may sell,  lease,  transfer or otherwise
dispose of any or all of its assets (upon  voluntary  liquidation or otherwise),
to the Borrower or another wholly-owned Subsidiary of the Borrower;


                                       51






     (l) the Borrower or any Subsidiary  may merge,  consolidate or combine with
another  entity  if  the  Borrower  or  the  Subsidiary,  respectively,  is  the
corporation surviving the merger; and

     (m) the Satellite Lease Arrangements.

     SECTION  5.17.  Employee  Contracts  and  Arrangements.  Neither the Parent
Guarantor  nor  the  Borrower  shall,   nor  shall  either  permit  any  of  its
Subsidiaries  to,  enter into any  employment  contracts or  arrangements  whose
terms, including salaries,  benefits and other compensation,  are not normal and
customary  and   commercially   reasonable   for  companies  of  like  size  and
circumstances.

     SECTION 5.18.  Investments.  Neither of the Parent  Guarantor nor any other
member of the Parent  Guarantor Group will make or acquire any Investment in any
Person other than:

     (a) Investments in Persons which are Subsidiaries on the date hereof;

     (b) Cash Equivalents; and

     (c) any Investment not otherwise permitted by the foregoing clauses of this
Section if, immediately after such Investment is made or acquired, the aggregate
net book value of all  Investments  permitted by this clause (c) does not exceed
$10,000,000.

     SECTION 5.19. Transactions with Affiliates.  Except where such Affiliate is
a member of the Parent  Guarantor Group, the Parent Guarantor will not, and will
not permit any  Subsidiary to,  directly or indirectly,  (i) pay any funds to or
for the account of any  Affiliate,  (ii) make any  investment  in any  Affiliate
(whether by acquisition of stock or indebtedness,  by loan, advance, transfer of
property,  guarantee or other agreement to pay, purchase or service, directly or
indirectly,  any Indebtedness,  or otherwise),  (iii) lease,  sell,  transfer or
otherwise dispose of any assets,  tangible or intangible,  to any Affiliate,  or
(iv) participate in, or effect,  any transaction  with any Affiliate,  except in
each case on an arm's-length  basis on terms at least as favorable to the Parent
Guarantor or such Subsidiary as could have been obtained from a third party that
was not an  Affiliate  or as  otherwise  expressly  approved  in  writing by the
Required Banks.

     SECTION 5.20.  Compliance with ERISA.  Neither the Parent Guarantor nor the
Borrower shall directly or indirectly,  and neither the Parent Guarantor nor the
Borrower shall permit any member of the Controlled  Group directly or indirectly
(i) to  terminate,  any  Qualified  Plan subject to Title IV of ERISA,  so as to




                                       52




result in any material (in the opinion of the Required  Banks)  liability to the
Borrower  or any  member of the  Controlled  Group,  (ii) to permit to exist any
ERISA  Event,  which  presents  the risk of a  material  (in the  opinion of the
Required  Banks)  liability of any member of the Controlled  Group,  or (iii) to
make a complete or partial withdrawal (within the meaning of ERISA Section 4201)
from any  Multiemployer  Plan so as to result in any material (in the opinion of
the  Required  Banks)  liability to any member of the  Controlled  Group or (iv)
permit the  present  value of all  nonforfeitable  accrued  benefits  under each
Qualified  Plan  (using  the  actuarial  assumptions  utilized  by the PBGC upon
termination  of a Qualified  Plan)  materially  (in the opinion of the  Required
Banks) to exceed the fair market  value of  Qualified  Plan assets  allocable to
such benefits, all determined as of the most recent valuation date for each such
Qualified Plan.

     SECTION 5.21. Restricted Payments. The Parent Guarantor will not declare or
make any dividend  payment or other  distribution of assets,  properties,  cash,
rights,  obligations  or securities on account of any shares of any class of its
capital stock or purchase,  redeem or otherwise acquire for value (or permit any
member of the Parent  Guarantor  Group to do so) any shares of its capital stock
or any  warrants,  rights or options to acquire  such  shares,  now or hereafter
outstanding.

     SECTION  5.22.  Accounting  Changes.  Neither the  Borrower  nor the Parent
Guarantor  will,  nor will permit any member of the Parent  Guarantor  Group to,
make any  significant  change in accounting  treatment and reporting  practices,
except as required by GAAP, or change the fiscal year of the Parent Guarantor or
any of its Subsidiaries.

     SECTION 5.23. Limitation on Indebtedness.  Neither the Parent Guarantor nor
the Borrower shall,  nor shall either permit any member of the Parent  Guarantor
Group (other than AMRC Holdings and  Subsidiaries  of AMRC Holdings) to, create,
incur, assume, guaranty, suffer to exist, or otherwise become or remain directly
or indirectly liable with respect to, any Indebtedness, except for:

     (a) accounts  payable to trade creditors for goods and services and current
operating liabilities (not the result of the borrowing of money) incurred in the
ordinary course of the Parent  Guarantor's,  the Borrower's or the  Subsidiary's
business, as the case may be, in accordance with customary terms and paid within
the specified time,  unless  contested in good faith by appropriate  proceedings
and reserved for in accordance with GAAP;

     (b) Indebtedness represented by Rate Contracts;



                                       53





     (c) income taxes payable and deferred taxes;

     (d) accrued expenses and deferred income;

     (e)  Indebtedness  under the Senior Notes in an aggregate  principal amount
not  to  exceed  $335,000,000  and  Contingent  Obligations  of  the  Borrower's
Subsidiaries  and of the Parent  Guarantor in respect  thereof (such  Contingent
Obligations  of the Parent  Guarantor  to be  subordinated  as  described in the
Offering Memorandum);

     (f) Indebtedness under the Term Credit Agreement;

     (g) Contingent  Obligations incurred in connection with any lease financing
of mobile communications terminals, not exceeding $5,000,000 in the aggregate in
principal amount;

     (h)  Indebtedness  outstanding  on the  Effective  Date and  identified  on
Schedule 5.23;

     (i) Indebtedness  under the Financial  Management Account Line of Credit of
the Borrower  payable to the order of Wachovia Bank of North Carolina,  N.A., in
an aggregate principal amount at any time not exceeding $2,500,000;

     (j)  Indebtedness  incurred to finance  In-Orbit  Insurance in an aggregate
amount outstanding at any time not to exceed $6,000,000;

     (k) Vendor Financing Indebtedness in an aggregate amount outstanding at any
time not to exceed $10,000,000; and

     (l) any other Indebtedness incurred after the Effective Date; provided that
the aggregate outstanding principal amount of all such Indebtedness shall not at
any time exceed $15,000,000.



                                    ARTICLE 6
                                    DEFAULTS

     SECTION 6.01.  Events of Default.  If one or more of the  following  events
("Events of Default") shall have occurred and be continuing:

     (a) the  Borrower  shall fail to pay any  principal of any Loan when due or
any interest, any fees or any other amount payable hereunder within two Business


                                       54





Days of the date when due, or one or more Shareholder Guarantors shall have made
more than two capital  contributions  or Investments in the Parent  Guarantor or
any Subsidiary thereof (or more than one during any twelve-month period) for the
principal  purpose of permitting  the Borrower to pay any  principal,  interest,
fees or other amounts payable hereunder;

     (b) the Borrower or the Parent  Guarantor  shall fail to observe or perform
any covenant contained in Article 5, other than those contained in Sections 5.01
through 5.05, 5.07 through 5.10, and 5.14;

     (c) the Borrower or the Parent  Guarantor  shall fail to observe or perform
any covenant or agreement  contained in this Agreement (other than those covered
by clause (a) or (b) above) for 20 days after  notice  thereof has been given to
the Borrower by the Administrative Agent at the request of any Bank;

     (d) any  representation,  warranty,  certification or statement made by the
Borrower, a Subsidiary of the Borrower or the Parent Guarantor in this Agreement
or any other Loan Document or in any certificate,  financial  statement or other
document delivered pursuant to this Agreement shall prove to have been incorrect
in any material respect when made (or deemed made);

     (e) the Parent  Guarantor or any Subsidiary of the Parent  Guarantor  shall
fail to make any payment in respect of (x) any obligation  under the Term Credit
Agreement  or (y) any other  Indebtedness  or  Contingent  Obligation  having an
aggregate  principal and face amount of more than $5,000,000,  in each case when
due (whether by scheduled maturity, required prepayment, acceleration, demand or
otherwise)  and such  failure  continues  after the  applicable  grace period or
notice period, if any, specified in the document relating thereto;

     (f) any event or condition shall occur which results in the acceleration of
the maturity of (x) any  Indebtedness  or Contingent  Obligation  under the Term
Credit Agreement or (y) any other  Indebtedness or Contingent  Obligation of the
Parent  Guarantor or any Subsidiary of the Parent  Guarantor having an aggregate
principal or face amount of more than $5,000,000 or enables (or, with the giving
of  notice  or lapse of time or  both,  would  enable)  the  holder  of any such
Indebtedness  or  Contingent  Obligation  or any Person  acting on such holder's
behalf to accelerate the maturity thereof;

     (g) the Parent  Guarantor  or any  Principal  Subsidiary  shall  commence a
voluntary case or other proceeding seeking liquidation,  reorganization or other
relief with respect to itself or its debts under any  bankruptcy,  insolvency or
other  similar law now or  hereafter in effect or seeking the  appointment  of a
trustee, receiver, liquidator,  custodian or other similar official of it or any




                                       55




substantial part of its property,  or shall consent to any such relief or to the
appointment of or taking  possession by any such official in an involuntary case
or other proceeding commenced against it, or shall make a general assignment for
the  benefit  of  creditors,  or shall fail  generally  to pay its debts as they
become  due,  or  shall  take  any  corporate  action  to  authorize  any of the
foregoing;

     (h) an involuntary case or other proceeding shall be commenced  against the
Parent Guarantor or any Principal Subsidiary seeking liquidation, reorganization
or other relief with respect to it or its debts under any bankruptcy, insolvency
or other similar law now or hereafter in effect or seeking the  appointment of a
trustee, receiver, liquidator,  custodian or other similar official of it or any
substantial part of its property,  and such involuntary case or other proceeding
shall remain  undismissed  and unstayed for a period of 60 days; or an order for
relief shall be entered against the Parent Guarantor or any Principal Subsidiary
under the federal bankruptcy laws as now or hereafter in effect;

     (i) (1) any  member of the  Controlled  Group  shall  fail to pay when due,
after the expiration of any applicable  grace period,  any  installment  payment
with respect to its withdrawal  liability  under a  Multiemployer  Plan; (2) any
member  of  the  Controlled   Group  shall  fail  to  satisfy  its  contribution
requirements  under Section 412(c)(11) of the Code, whether or not it has sought
a waiver  under  Section  412(d) of the Code;  (3) in the case of an ERISA Event
involving the withdrawal from a Plan of a "substantial  employer" (as defined in
Section  4001(a)(2) or Section  4062(e) of ERISA),  the  withdrawing  employer's
proportionate  share of that Plan's  Unfunded  Pension  Liabilities is more than
$5,000,000  or 10% of its net  worth,  if  greater;  (4) in the case of an ERISA
Event involving the complete or partial  withdrawal  from a Multiemployer  Plan,
the  withdrawing  employer has  incurred a withdrawal  liability in an aggregate
amount exceeding $5,000,000 or 10% of its net worth, if greater; (5) in the case
of an ERISA  Event not  described  in clause (3) or (4),  the  Unfunded  Pension
Liabilities  of the relevant  Plan or Plans exceed  $5,000,000 or 10% of its net
worth,  if greater;  (6) a Plan that is intended to be qualified  under  Section
401(a) of the Code shall lose its qualification,  and the loss can reasonably be
expected  to  impose  on any  member  of the  Controlled  Group  liability  (for
additional taxes, to Plan participants, or otherwise) in the aggregate amount of
$5,000,000 or 10% of its net worth, if greater or more; (7) the  commencement or
increase of  contributions  to, the adoption of, or the  amendment of a Plan by,
any member of the  Controlled  Group shall  result in a net increase in unfunded
liabilities to the Borrower or an ERISA Affiliate in excess of $5,000,000 or 10%
of net worth,  if greater;  or (8) the  occurrence of any  combination of events
listed in clauses  (3)  through (7) that  involves a net  increase in  aggregate
Unfunded Pension Liabilities and unfunded liabilities in excess of $5,000,000 or
10% of its net worth, if greater;




                                       56





     (j) one or more final judgments, orders or decrees shall be entered against
the Parent  Guarantor or any member of the Parent  Guarantor  Group involving in
the  aggregate a liability  (not fully  covered by insurance and as to which the
insurer has not acknowledged liability) more than an amount equal to the greater
of (i) $5,000,000 and (ii) 10% of the Parent Guarantor's net worth, and the same
shall remain unvacated, undischarged,  unstayed or unbonded pending appeal for a
period of 60 days after the entry thereof; or

     (k) any  non-monetary  judgment,  order or decree shall be rendered against
the Parent  Guarantor  or any of its  Subsidiaries  which  could  reasonably  be
expected to have a Material Adverse Effect,  and enforcement  proceedings  shall
have been commenced by any Person upon such judgment or order which shall remain
unstayed for any period of 10 consecutive days or more; or

     (l) the FCC or any other  Governmental  Authority  shall  revoke or fail to
renew any FCC License or any other material license,  permit or franchise of the
Parent Guarantor or any of its  Subsidiaries;  the Borrower shall for any reason
lose any FCC License or any other material license,  permit or franchise; or the
Borrower  shall  suffer  the  imposition  of  any  restraining  order,   escrow,
suspension or impound of funds in connection  with any  proceeding  (judicial or
administrative)  with respect to any FCC License or any other material  license,
permit or franchise;

     (m) there shall occur and be continuing a Material Adverse Effect;

     (n) the Borrower  shall breach or default  under any Rate Contract to which
any Bank is a party,  if the  effect of such  breach or  default is to allow the
Bank to proceed  against the  Borrower to satisfy any claim of the Bank  against
the Borrower in respect of such Rate Contract;

     (o) any  provision of Article 9 of this  Agreement  shall for any reason be
revoked or invalidated, or otherwise cease to be in full force and effect;

     (p) there shall occur a Change in Control;

     (q) any Shareholder  Guarantor (other than Baron Capital,  so long as, with
respect to any failure to make a payment  described  in clause  (ii)  below,  an
amount equal to such payment is paid under the Baron  Capital  Letter of Credit)
shall fail to make any payment (i) in respect of any  Indebtedness or Contingent
Obligation having an aggregate principal or face amount of more than $75,000,000
or (ii) under its Shareholder  Guaranty when due (whether by scheduled maturity,



                                       57




required  prepayment,  acceleration,  demand  or  otherwise)  and  such  failure
continues after the applicable grace period or notice period, if any,  specified
in the document relating thereto;

     (r) any event or condition shall occur which results in the acceleration of
the maturity of any  Indebtedness  or Contingent  Obligation of any  Shareholder
Guarantor  (other than Baron  Capital)  having an  aggregate  principal  or face
amount of more than  $75,000,000 or enables the holder of such  Indebtedness  or
Contingent Obligation or any Person acting on such holder's behalf to accelerate
the maturity thereof;

     (s) any  Shareholder  Guaranty or the Baron Capital  Letter of Credit shall
for any reason be revoked or invalidated or otherwise  cease to be in full force
and effect (other than in accordance with its terms as the result of performance
in full of the relevant Shareholder  Guarantor's  obligations thereunder) or any
Shareholder  Guarantor  (other than Baron Capital) shall so assert in writing or
any  Shareholder  Guarantor  shall  bring an  action  to limit  its  liabilities
thereunder;

     (t) Hughes' senior  unsecured  long-term  securities  (without  third-party
credit  enhancement)  shall not be rated  Baa3 or above by  Moody's  and BBB- or
above by S&P; or

     (u) Hughes and either other  Shareholder  Guarantor shall have notified any
of the Agents and the banks of the  existence of a Guaranty  Issuance  Agreement
Event of Default;

then, and in every such event, the  Administrative  Agent shall (i) if requested
by Banks having more than 50% in aggregate amount of the Commitments,  by notice
to the Borrower  terminate the Commitments  and they shall thereupon  terminate,
and (ii) if requested by Banks holding more than 50% of the aggregate  principal
amount of the Loans, by notice to the Borrower  declare the Loans (together with
accrued  interest  thereon)  to  be,  and  the  Loans  shall  thereupon  become,
immediately due and payable without presentment, demand, protest or other notice
of any kind,  all of which are hereby waived by the  Borrower;  provided that in
the case of any of the  Events of Default  specified  in clause (g) or (h) above
with  respect to the  Borrower,  without any notice to the Borrower or any other
act by the  Administrative  Agent or the Banks, the Commitments  shall thereupon
terminate and the Loans  (together with accrued  interest  thereon) shall become
immediately due and payable without presentment, demand, protest or other notice
of any kind,  all of which are  hereby  waived by the  Borrower.  If any  amount
payable under this Agreement shall not be paid when due, then the Administrative
Agent  shall,  if  requested  by Banks  holding  more than 50% of the  aggregate
principal  amount  (excluding any Loans held by the Borrower or any  Shareholder




                                       58




Guarantor or any Affiliate of the  foregoing) of the Tranche A Loans,  Tranche B
Loans or Tranche C Loans,  as the case may be, demand payment  thereof under the
relevant Shareholder Guaranty.

     SECTION 6.02. Notice of Default. The Administrative Agent shall give notice
to the Borrower under Section 6.01(c)  promptly upon being requested to do so by
any Bank and shall thereupon notify all the Banks thereof.



                                    ARTICLE 7
                                   THE AGENTS

     SECTION 7.01. Appointment and Authorization. Each Bank irrevocably appoints
and  authorizes  each  Agent to take such  action as agent on its  behalf and to
exercise  such  powers  under  this  Agreement,  the Notes and each  other  Loan
Document as are delegated to such Agent by the terms hereof or thereof, together
with all such powers as are reasonably incidental thereto.

     SECTION 7.02.  Agents and Affiliates.  Morgan Guaranty Trust Company of New
York shall have the same  rights and powers  under this  Agreement  as any other
Bank and may exercise or refrain from  exercising the same as though it were not
an Agent, and each of Toronto Dominion  (Texas),  Inc. and Morgan Guaranty Trust
Company of New York and its affiliates may accept  deposits from, lend money to,
and generally  engage in any kind of business  with the Parent  Guarantor or any
Subsidiary or affiliate of the Parent Guarantor as if it were not an Agent.

     SECTION 7.03. Action by Agents. The obligations of the Agents hereunder are
only those  expressly set forth herein.  Without  limiting the generality of the
foregoing,  the Agents  shall not be required to take any action with respect to
any Default, except as expressly provided in Article 6.

     SECTION  7.04.  Consultation  with  Experts.  Either Agent may consult with
legal  counsel  (who may be counsel for the  Borrower or the Parent  Guarantor),
independent public accountants and other experts selected by it and shall not be
liable  for any  action  taken or  omitted  to be  taken by it in good  faith in
accordance with the advice of such counsel, accountants or experts.

     SECTION 7.05. Liability of Agents. No Agent or any of its affiliates or any
of their respective directors, officers, agents or employees shall be liable for
any action taken or not taken by it in connection  herewith (i) with the consent
or at the request of the Required  Banks or (ii) in the absence of its own gross
negligence or willful  misconduct.  No Agent or any of its  affiliates or any of
their respective directors,  officers,  agents or employees shall be responsible



                                       59




for or have any duty to  ascertain,  inquire  into or verify (i) any  statement,
warranty  or  representation  made in  connection  with  this  Agreement  or any
borrowing hereunder;  (ii) the performance or observance of any of the covenants
or agreements of the Borrower or the Parent Guarantor; (iii) the satisfaction of
any  condition  specified in Article 3, except  receipt of items  required to be
delivered to the  Documentation  Agent; or (iv) the validity,  effectiveness  or
genuineness  of this  Agreement,  the Notes or any other  instrument  or writing
furnished in connection  herewith.  No Agent shall incur any liability by acting
in reliance upon any notice, consent,  certificate,  statement, or other writing
(which may be a bank wire,  telex,  facsimile  transmission or similar  writing)
believed by it to be genuine or to be signed by the proper party or parties.

     SECTION 7.06. Indemnification.  Each Bank shall, ratably in accordance with
its  Commitment,  indemnify  each Agent,  its  affiliates  and their  respective
directors,  officers,  agents and employees (to the extent not reimbursed by the
Borrower or the Parent Guarantor)  against any cost,  expense (including counsel
fees and disbursements),  claim, demand,  action, loss or liability (except such
as result from such  indemnitee's  gross negligence or willful  misconduct) that
such  indemnitee  may suffer or incur in connection  with this  Agreement or any
action taken or omitted by such indemnitee hereunder.

     SECTION  7.07.  Credit  Decision.  Each  Bank  acknowledges  that  it  has,
independently  and without  reliance  upon either  Agent or any other Bank,  and
based on such documents and information as it has deemed  appropriate,  made its
own credit  analysis and decision to enter into this  Agreement.  Each Bank also
acknowledges that it will,  independently and without reliance upon either Agent
or any other Bank, and based on such documents and  information as it shall deem
appropriate at the time,  continue to make its own credit decisions in taking or
not taking any action under this Agreement.

     SECTION  7.08.  Successor  Agent.  Either  Agent may  resign at any time by
giving notice thereof to the Banks and the Borrower.  Upon any such resignation,
the  Required  Banks  shall have the right to appoint a successor  Agent.  If no
successor  Agent shall have been so appointed by the Required  Banks,  and shall
have accepted such  appointment,  within 30 days after the retiring  Agent gives
notice of  resignation,  then the  retiring  Agent may,  on behalf of the Banks,
appoint a  successor  Agent,  which  shall be a  commercial  bank  organized  or
licensed  under the laws of the United States of America or of any State thereof
and having a combined  capital  and  surplus of at least  $50,000,000.  Upon the
acceptance of its  appointment  as Agent  hereunder by a successor  Agent,  such
successor Agent shall thereupon succeed to and become vested with all the rights
and duties of the retiring  Agent,  and the retiring  Agent shall be  discharged
from  its  duties  and  obligations   hereunder.   After  any  retiring  Agent's



                                       60




resignation  hereunder as Agent,  the  provisions of this Article shall inure to
its  benefit as to any  actions  taken or omitted to be taken by it while it was
Agent.

     SECTION 7.09.  Agents' Fees.  The Borrower  shall pay to each Agent for its
own account fees in the amounts and at the times previously  agreed upon between
the Borrower and such Agent.



                                    ARTICLE 8
                             CHANGE IN CIRCUMSTANCES

     SECTION 8.01. Basis for Determining  Interest Rate Inadequate or Unfair. If
on or prior to the first day of any Interest Period for any Euro-Dollar Loan:

     (a) the  Administrative  Agent  is  advised  by the  Reference  Banks  that
deposits in dollars (in the  applicable  amounts)  are not being  offered to the
Reference Banks in the London interbank market for such Interest Period, or

     (b)  Banks  having  50% or more of the  aggregate  principal  amount of the
affected  Loans  advise  the  Administrative  Agent  that  the  Adjusted  London
Interbank  Offered  Rate as  determined  by the  Administrative  Agent  will not
adequately  and  fairly  reflect  the  cost  to  such  Banks  of  funding  their
Euro-Dollar  Loans for such  Interest  Period,  the  Administrative  Agent shall
forthwith give notice thereof to the Borrower and the Banks, whereupon until the
Administrative Agent notifies the Borrower that the circumstances giving rise to
such  suspension  no  longer  exist,  (i) the  obligations  of the Banks to make
Euro-Dollar  Loans  or to  continue  or  convert  outstanding  Loans  as or into
Euro-Dollar Loans shall be suspended and (ii) each outstanding  Euro-Dollar Loan
shall be  converted  into a Base Rate  Loan on the last day of the then  current
Interest  Period   applicable   thereto.   Unless  the  Borrower   notifies  the
Administrative  Agent at least two Domestic Business Days before the date of any
Euro-Dollar  Borrowing for which a Notice of Borrowing has previously been given
that it elects not to borrow on such date,  such Borrowing shall instead be made
as a Base Rate Borrowing.  The Administrative Agent shall notify the Borrower as
soon as reasonably possible upon learning that the circumstances  giving rise to
such suspension no longer exist.

     SECTION 8.02. Illegality.  If, on or after the date of this Agreement,  the
adoption  of any  applicable  law,  rule or  regulation,  or any  change  in any
applicable  law,  rule or  regulation,  or any change in the  interpretation  or
administration thereof by any governmental authority, central bank or comparable




                                       61




agency charged with the interpretation or administration  thereof, or compliance
by any Bank (or its  Euro-Dollar  Lending  Office) with any request or directive
(whether or not having the force of law) of any such authority,  central bank or
comparable  agency  shall make it  unlawful or  impossible  for any Bank (or its
Euro-Dollar  Lending Office) to make, maintain or fund its Euro-Dollar Loans and
such Bank shall so notify the  Administrative  Agent, the  Administrative  Agent
shall  forthwith  give  notice  thereof  to the other  Banks  and the  Borrower,
whereupon  until such Bank  notifies the Borrower and the  Administrative  Agent
that the  circumstances  giving rise to such  suspension  no longer  exist,  the
obligation of such Bank to make  Euro-Dollar  Loans,  or to convert  outstanding
Loans into Euro-Dollar  Loans,  shall be suspended.  Before giving any notice to
the Administrative  Agent pursuant to this Section,  such Bank shall designate a
different Euro-Dollar Lending Office if such designation will avoid the need for
giving  such notice and will not, in the  judgment  of such Bank,  be  otherwise
disadvantageous  to such Bank. If such notice is given, each Euro-Dollar Loan of
such Bank then outstanding  shall be converted to a Base Rate Loan either (a) on
the last day of the then current Interest Period  applicable to such Euro-Dollar
Loan if such Bank may  lawfully  continue to maintain and fund such Loan to such
day or (b)  immediately  if such Bank shall  determine  that it may not lawfully
continue to maintain and fund such Loan to such day.  Each Bank shall notify the
Administrative  Agent and the Borrower as soon as reasonably  possible after the
circumstances  giving  rise to any  suspension  by such Bank  described  in this
Section 8.02 no longer exist.

     SECTION 8.03.  Increased  Cost and Reduced  Return.  (a) If on or after the
date hereof,  the adoption of any  applicable  law, rule or  regulation,  or any
change  in  any  applicable  law,  rule  or  regulation,  or any  change  in the
interpretation or administration thereof by any governmental authority,  central
bank or comparable  agency  charged with the  interpretation  or  administration
thereof,  or compliance by any Bank (or its Applicable  Lending Office) with any
request  or  directive  (whether  or not  having  the  force of law) of any such
authority,  central  bank or  comparable  agency  shall  impose,  modify or deem
applicable any reserve  (including,  without  limitation,  any such  requirement
imposed by the Board of Governors of the Federal Reserve  System,  but excluding
any such requirement included in an applicable  Euro-Dollar Reserve Percentage),
special deposit,  insurance assessment or similar requirement against assets of,
deposits  with or for the  account of, or credit  extended  by, any Bank (or its
Applicable  Lending  Office)  or shall  impose  on any  Bank (or its  Applicable
Lending Office) or the London interbank market any other condition affecting its
Euro-Dollar  Loans, its Note or its obligation to make Euro-Dollar Loans and the
result  of any of the  foregoing  is to  increase  the cost to such Bank (or its
Applicable  Lending Office) of making or maintaining any Euro-Dollar Loan, or to
reduce  the  amount  of any sum  received  or  receivable  by such  Bank (or its
Applicable  Lending  Office) under this Agreement or under its Note with respect



                                       62




thereto,  by an amount deemed by such Bank to be material,  then, within 15 days
after  demand  by  such  Bank  (with a copy to the  Administrative  Agent),  the
Borrower  shall pay to such  Bank such  additional  amount  or  amounts  as will
compensate  such Bank for such increased cost or reduction;  provided,  however,
that in the case of an increase  referred to above  resulting from the published
interpretation by a governmental authority,  such Bank shall be entitled to make
demand  on  the  Borrower  in  respect  thereof  only  within  180  days  of the
publication of such interpretation.

     (b) If any Bank shall have  determined  that,  after the date  hereof,  the
adoption of any applicable law, rule or regulation  regarding  capital adequacy,
or any  change  in any  such  law,  rule or  regulation,  or any  change  in the
interpretation or administration thereof by any governmental authority,  central
bank or comparable  agency  charged with the  interpretation  or  administration
thereof,  or any request or directive regarding capital adequacy (whether or not
having  the  force of law) of any such  authority,  central  bank or  comparable
agency,  has or would have the effect of reducing  the rate of return on capital
of such  Bank  (or its  Parent)  as a  consequence  of such  Bank's  obligations
hereunder  to a level  below  that which  such Bank (or its  Parent)  could have
achieved  but for such  adoption,  change,  request or  directive  (taking  into
consideration its policies with respect to capital adequacy) by an amount deemed
by such Bank to be material, then from time to time, within 15 days after demand
by such Bank (with a copy to the  Administrative  Agent), the Borrower shall pay
to such Bank such additional  amount or amounts as will compensate such Bank (or
its  Parent)  for  such  reduction;  provided,  however,  that in the case of an
increase  referred to above  resulting  from the published  interpretation  by a
governmental  authority,  such  Bank  shall be  entitled  to make  demand on the
Borrower  in respect  thereof  only within 180 days of the  publication  of such
interpretation.

     (c) Each Bank will  promptly  notify the  Borrower  and the  Administrative
Agent of any event of which it has knowledge,  occurring  after the date hereof,
which will entitle such Bank to  compensation  pursuant to this Section and will
designate a different  Lending  Office if such  designation  will avoid the need
for, or reduce the amount of, such compensation and will not, in the judgment of
such Bank, be otherwise  disadvantageous to such Bank. A certificate of any Bank
claiming compensation under this Section and setting forth the additional amount
or amounts to be paid to it  hereunder  shall be  conclusive  in the  absence of
manifest  error.  In determining  such amount,  such Bank may use any reasonable
averaging  and  attribution  methods.  Each Bank will notify the  Administrative
Agent and the Borrower as soon as  reasonably  possible  after any  circumstance
entitling such Bank to  compensation  pursuant to this Section 8.03(c) no longer
exists.



                                       63





     SECTION  8.04.  Taxes.  (a) For the  purposes  of this  Section  8.04 , the
following terms have the following meanings:

     "Taxes" means any and all present or future taxes, duties, levies, imposts,
deductions,  charges or withholdings with respect to any payment by the Borrower
or the Parent Guarantor, as the case may be, pursuant to this Agreement or under
any Note, and all liabilities with respect thereto, excluding (i) in the case of
each Bank and Agent, taxes imposed on its income, and franchise or similar taxes
imposed on it, by a jurisdiction  under the laws of which such Bank or Agent (as
the case may be) is  organized  or in which its  principal  executive  office is
located or, in the case of each Bank, in which its Applicable  Lending Office is
located and (ii) in the case of each Bank,  any United  States  withholding  tax
imposed on such  payments  but only to the  extent  that such Bank is subject to
United  States  withholding  tax at the time such Bank first  becomes a party to
this Agreement.

     "Other  Taxes" means any present or future stamp or  documentary  taxes and
any other excise or property taxes,  or similar  charges or levies,  which arise
from any payment made  pursuant to this  Agreement or under any Note or from the
execution or delivery of, or  otherwise  with respect to, this  Agreement or any
Note.

     (b) Any and all payments by the Borrower or the Parent  Guarantor to or for
the  account  of any Bank or Agent  hereunder  or under  any Note  shall be made
without  deduction for any Taxes or Other Taxes;  provided that, if the Borrower
or the Parent  Guarantor  shall be  required by law to deduct any Taxes or Other
Taxes  from  any such  payments,  (i) the sum  payable  shall  be  increased  as
necessary  so that after making all required  deductions  (including  deductions
applicable to additional sums payable under this Section) such Bank or Agent (as
the case may be) receives an amount equal to the sum it would have  received had
no such deductions been made, (ii) the Borrower or the Parent Guarantor,  as the
case may be, shall make such  deductions,  (iii) the Borrower shall pay the full
amount  deducted  to the  relevant  taxation  authority  or other  authority  in
accordance with applicable law and (iv) the Borrower or the Parent Guarantor, as
the case may be,  shall  furnish to the  Administrative  Agent,  at its  address
referred to in Section  10.01 , the  original  or a certified  copy of a receipt
evidencing payment thereof.

     (c) The  Borrower  agrees  to  indemnify  each  Bank and Agent for the full
amount of Taxes or Other  Taxes  (including,  without  limitation,  any Taxes or
Other Taxes  imposed or asserted by any  jurisdiction  on amounts  payable under
this  Section) paid by such Bank or Agent (as the case may be) and any liability
(including penalties, interest and expenses, other than those resulting from any
act or failure to act by such Bank) arising  therefrom or with respect  thereto.




                                       64




This  indemnification  shall be paid within 15 days after such Bank or Agent (as
the case may be) makes demand therefor.

     (d) Each Bank organized under the laws of a jurisdiction outside the United
States,  on or prior to the date of its execution and delivery of this Agreement
in the case of each Bank listed on the signature pages hereof and on or prior to
the date on which it  becomes a Bank in the case of each  other  Bank,  and from
time to time  thereafter  if requested  in writing by the Borrower  (but only so
long as such Bank remains  lawfully  able to do so),  shall provide the Borrower
and the Administrative Agent with Internal Revenue Service form 1001 or 4224, as
appropriate,  or any successor form prescribed by the Internal  Revenue Service,
certifying  that such Bank is entitled to benefits under an income tax treaty to
which the United  States is a party which  exempts  the Bank from United  States
withholding  tax or reduces the rate of withholding  tax on payments of interest
for the account of such Bank or certifying that the income  receivable  pursuant
to this  Agreement  is  effectively  connected  with the  conduct  of a trade or
business in the United States.

     (e) For any period  with  respect to which a Bank has failed to provide the
Borrower  or the  Administrative  Agent with the  appropriate  form  pursuant to
Section  8.04(d)  (unless  such  failure  is due to a change in  treaty,  law or
regulation  occurring  subsequent to the date on which such form  originally was
required to be  provided),  such Bank shall not be  entitled to  indemnification
under  Section  8.04(b) or 8.04(c) with  respect to Taxes  imposed by the United
States;  provided that if a Bank, which is otherwise exempt from or subject to a
reduced rate of withholding tax, becomes subject to Taxes because of its failure
to deliver a form required hereunder, the Borrower shall take such steps as such
Bank shall reasonably request to assist such Bank to recover such Taxes.

     (f) If the Borrower or the Parent  Guarantor is required to pay  additional
amounts to or for the account of any Bank  pursuant to this  Section,  then such
Bank will change the  jurisdiction  of its Applicable  Lending Office if, in the
judgment  of such  Bank,  such  change  (i) will  eliminate  or reduce  any such
additional  payment  which  may  thereafter  accrue  and  (ii) is not  otherwise
disadvantageous to such Bank.

     SECTION 8.05. Base Rate Loans Substituted for Affected  Euro-Dollar  Loans.
If (i) the  obligation  of any Bank to make,  or convert  outstanding  Loans to,
Euro-Dollar  Loans has been suspended  pursuant to Section 8.02 or (ii) any Bank
has  demanded  compensation  under  Section  8.03 or 8.04  with  respect  to its
Euro-Dollar Loans and the Borrower shall, by at least five Euro-Dollar  Business
Days' prior notice to such Bank through the  Administrative  Agent, have elected
that the provisions of this Section shall apply to such Bank,  then,  unless and



                                       65




until such Bank notifies the Borrower that the circumstances giving rise to such
suspension or demand for compensation no longer exist:

     (a) all Loans which would  otherwise be made by such Bank as (or  continued
as or converted  into)  Euro-Dollar  Loans shall  instead be Base Rate Loans (on
which interest and principal shall be payable contemporaneously with the related
Euro-Dollar Loans of the other Banks); and

     (b) after each of its Euro-Dollar  Loans has been repaid (or converted to a
Base Rate Loan),  all payments of principal  which would otherwise be applied to
repay  such  Euro-Dollar  Loans  shall be  applied  to repay its Base Rate Loans
instead.

If such Bank  notifies the Borrower that the  circumstances  giving rise to such
notice no longer apply,  the principal  amount of each such Base Rate Loan shall
be converted  into a  Euro-Dollar  Loan on the first day of the next  succeeding
Interest Period applicable to the related Euro-Dollar Loans of the other Banks.



                                    ARTICLE 9
                                 PARENT GUARANTY

     SECTION  9.01.   The  Parent   Guaranty.   The  Parent   Guarantor   hereby
unconditionally  guarantees  the full and  punctual  payment  (whether at stated
maturity,  upon  acceleration  or otherwise) of the principal of and interest on
each Note issued by the Borrower  pursuant to this  Agreement,  and the full and
punctual  payment  of all other  amounts  payable  by the  Borrower  under  this
Agreement.  Upon failure by the Borrower to pay punctually any such amount,  the
Parent  Guarantor  shall  forthwith  on demand pay the amount not so paid at the
place and in the manner specified in this Agreement.

     SECTION  9.02.  Guaranty  Unconditional.  The  obligations  of  the  Parent
Guarantor  hereunder shall be  unconditional  and absolute and, without limiting
the generality of the foregoing, shall not be released,  discharged or otherwise
affected by:

     (a) any extension,  renewal, settlement,  compromise,  waiver or release in
respect of any  obligation of the Borrower  under this Agreement or any Note, by
operation of law or otherwise;

     (b) any modification or amendment of or supplement to this Agreement or any
Note;


                                       66






     (c) any release, impairment,  non-perfection or invalidity of any direct or
indirect security for any obligation of the Borrower under this Agreement or any
Note;

     (d) any change in the  corporate  existence,  structure or ownership of the
Borrower,  or  any  insolvency,  bankruptcy,  reorganization  or  other  similar
proceeding  affecting  the  Borrower or its assets or any  resulting  release or
discharge of any  obligation of the Borrower  contained in this Agreement or any
Note;

     (e) the  existence  of any claim,  set-off or other rights which the Parent
Guarantor may have at any time against the Borrower,  either Agent,  any Bank or
any other Person, whether in connection herewith or any unrelated  transactions,
provided  that nothing  herein shall  prevent the assertion of any such claim by
separate suit or compulsory counterclaim;

     (f) any invalidity or unenforceability  relating to or against the Borrower
for any reason of this Agreement or any Note, or any provision of applicable law
or  regulation  purporting  to  prohibit  the  payment  by the  Borrower  of the
principal of or interest on any Note or any other amount payable by the Borrower
under this Agreement; or

     (g) any other act or omission to act or delay of any kind by the  Borrower,
either Agent, any Bank or any other Person or any other circumstance  whatsoever
which might,  but for the  provisions of this  paragraph,  constitute a legal or
equitable discharge of the Parent Guarantor's obligations hereunder.

     SECTION 9.03.  Discharge Only Upon Payment in Full;  Restatement in Certain
Circumstances. The Parent Guarantor's obligations hereunder shall remain in full
force and effect until the  Commitments  shall have terminated and the principal
of and interest on the Notes and all other amounts payable by the Borrower under
this  Agreement  shall have been paid in full. If at any time any payment of the
principal of or interest on any Note or any other amount payable by the Borrower
under this Agreement is rescinded or must be otherwise restored or returned upon
the insolvency,  bankruptcy or reorganization of the Borrower or otherwise,  the
Parent Guarantor's  obligations  hereunder with respect to such payment shall be
reinstated at such time as though such payment had been due but not made at such
time.

     SECTION  9.04.  Waiver  by  the  Parent  Guarantor.  The  Parent  Guarantor
irrevocably  waives  acceptance  hereof,  presentment,  demand,  protest and any



                                       67




notice not provided for herein,  as well as any requirement that at any time any
action be taken by any Person against the Borrower or any other Person.

     SECTION 9.05. Subrogation. Until such time as all principal of and interest
on each Note issued by the  Borrower  pursuant to this  Agreement  and all other
amounts payable by the Borrower under this Agreement have indefeasibly been paid
in full,  the  Parent  Guarantor  shall not assert any rights to which it may be
entitled, by operation of law or otherwise, upon making any payment hereunder to
be  subrogated  to the rights of the payee  against the Borrower with respect to
such payment or against any direct or indirect security  therefor,  or otherwise
to be  reimbursed,  indemnified  or  exonerated  by or for  the  account  of the
Borrower in respect thereof.

     SECTION 9.06. Stay of Acceleration. If acceleration of the time for payment
of any amount payable by the Borrower under this Agreement or any Note is stayed
upon insolvency,  bankruptcy or reorganization of the Borrower, all such amounts
otherwise  subject  to  acceleration  under  the terms of this  Agreement  shall
nonetheless be payable by the Parent Guarantor  hereunder forthwith on demand by
the Administrative  Agent made at the request of the requisite proportion of the
Banks specified in Article 6 of the Agreement.

     SECTION 9.07.  Subordination.  (a) The obligations of the Parent  Guarantor
under  this  Article 9 will be  subordinated  in right of  payment  to the prior
payment in full of all Senior Indebtedness.

     (b) Upon  any  distribution  to  creditors  of the  Parent  Guarantor  in a
liquidation  or  dissolution  of  the  Parent  Guarantor  or  in  a  bankruptcy,
reorganization,  insolvency,  receivership or similar proceeding relating to the
Parent Guarantor or its property,  an assignment for the benefit of creditors or
any marshalling of the Parent Guarantor's assets and liabilities, the holders of
Senior  Indebtedness  will  be  entitled  to  receive  payment  in  full  of all
Obligations with respect to Senior  Indebtedness  (including  interest after the
commencement  of any such  proceeding  at the rate  specified in the Term Credit
Agreement or otherwise  applicable thereto) before the Banks will be entitled to
receive any payment under this Article 9, and until all Obligations with respect
to Senior  Indebtedness  are paid in full, any  distribution  to which the Banks
would be entitled  shall be made to the holders of Senior  Indebtedness  (except
that the Banks may receive and retain Permitted Junior Securities).

     (c) The Parent Guarantor may not make any payment upon or in respect of its
obligations under this Article 9 (except in Permitted Junior  Securities) if (i)
a default in the payment of the  principal of,  premium,  if any, or interest on
Designated  Senior  Indebtedness  occurs and is continuing beyond any applicable


                                       68





period of grace or (ii) any other  default  occurs  with  respect to  Designated
Senior  Indebtedness that permits holders of the Designated Senior  Indebtedness
as  to  which  such  default   relates  to  accelerate   its  maturity  and  the
Administrative  Agent  receives  notice of such  default  (a  "Payment  Blockage
Notice")  from the Parent  Guarantor  or the  holders of any  Designated  Senior
Indebtedness.  Payments under this Article 9 may and shall be resumed (i) in the
case of a  payment  default,  upon the date on which  such  default  is cured or
waived and (ii) in the case of a nonpayment default,  the earlier of the date on
which such  nonpayment  default is cured or waived or 179 days after the date on
which the applicable Payment Blockage Notice is received, unless the maturity of
any  Designated  Senior  Indebtedness  has been  accelerated.  No new  period of
payment  blockage  may be  commenced  unless and until (i) 360 days have elapsed
since the  effectiveness  of the immediately  prior Payment  Blockage Notice and
(ii) all scheduled payments of principal,  premium,  if any, and interest on the
Notes that have come due have been paid in full with cash. No nonpayment default
that existed or was  continuing on the date of delivery of any Payment  Blockage
Notice  to the  Administrative  Agent  shall  be,  or be made,  the  basis for a
subsequent Payment Blockage Notice.

     (d)  The  Parent   Guarantor   shall  promptly  notify  holders  of  Senior
Indebtedness  if  payment  of the Loans is  accelerated  because  of an Event of
Default.

     (e) As used in this Section 9.07, the following  capitalized terms have the
meanings set forth below:

     "Capital  Stock" means (i) in the case of a corporation,  corporate  stock,
(ii) in the case of an  association  or  business  entity,  any and all  shares,
interests,  participations,  rights or other equivalents (however designated) of
corporate  stock,  (iii)  in the  case of a  partnership  or  limited  liability
company,  partnership or membership  interests  (whether general or limited) and
(iv) any other interest or  participation  that confers on a Person the right to
receive a share of the profits and losses of, or distributions of assets of, the
issuing Person.

     "Designated  Senior  Indebtedness"  means (i) any Indebtedness  outstanding
under the Loan  Documents (as defined in the Term Credit  Agreement) or (ii) any
other Senior  Indebtedness  the principal amount of which is $25,000,000 or more
and  that  has  been  designated  by the  Parent  Guarantor  in  writing  to the
Administrative Agent as "Designated Senior Indebtedness".

     "Equity  Interests" means Capital Stock and all warrants,  options or other
rights to  acquire  Capital  Stock  (but  excluding  any debt  security  that is
convertible into, or exchangeable for, Capital Stock).


                                       69





     "Permitted  Junior   Securities"  means  Equity  Interests  in  the  Parent
Guarantor or debt  securities that are  subordinated to all Senior  Indebtedness
(and  any debt  securities  issued  in  exchange  for  Senior  Indebtedness)  to
substantially  the same extent as, or to a greater extent than, the  obligations
of  the  Parent  Guarantor  under  this  Article  9 are  subordinated  to  Senor
Indebtedness.

     "Senior  Indebtedness"  means  Obligations in respect of the Loan Documents
(as  defined in the Term Credit  Agreement)  and any other  Indebtedness  of the
Parent Guarantor now or hereafter incurred except such Indebtedness specifically
designated  by the Parent  Guarantor in writing to the  Administrative  Agent as
subordinated  indebtedness  at  the  time  of  its  incurrence.  Notwithstanding
anything to the contrary in the foregoing,  Senior Indebtedness will not include
(i) any liability for federal,  state, local or other taxes owed or owing by the
Parent  Guarantor,  (ii) any  Indebtedness of the Parent Guarantor to any of its
Subsidiaries  or  other  Affiliates,  (iii)  any  trade  payables  or  (iv)  any
Indebtedness that is incurred in violation of this Agreement.



                                   ARTICLE 10
                                  MISCELLANEOUS

     SECTION 10.01.  Notices. All notices,  requests and other communications to
any  party  hereunder  shall  be in  writing  (including  bank  wire,  facsimile
transmission  or similar  writing) and shall be given to such party:  (a) in the
case of the Borrower,  the Parent  Guarantor or either Agent,  at its address or
facsimile number set forth on the signature pages hereof, (b) in the case of any
Bank,  at its  address  or  facsimile  number  set  forth in its  Administrative
Questionnaire  or (c) in the case of any party,  such other address or facsimile
number as such  party may  hereafter  specify  for the  purpose by notice to the
Agents and the Borrower.  Each such notice, request or other communication shall
be effective (i) if given by facsimile  transmission,  when  transmitted  to the
facsimile  number  specified  in this  Section  and  confirmation  of receipt is
received,  (ii) if given by mail, 72 hours after such communication is deposited
in the mails with first class postage  prepaid,  addressed as aforesaid or (iii)
if given by any other means,  when  delivered  at the address  specified in this
Section;  provided that notices to the  Administrative  Agent under Article 2 or
Article 8 shall not be effective until received.

     SECTION 10.02. No Waivers.  No failure or delay by either Agent or any Bank
in exercising  any right,  power or privilege  hereunder or under any Note shall
operate as a waiver  thereof  nor shall any single or partial  exercise  thereof
preclude  any other or further  exercise  thereof or the  exercise  of any other



                                       70




right,  power or privilege.  The rights and remedies  herein  provided  shall be
cumulative and not exclusive of any rights or remedies provided by law.

     SECTION 10.03.  Expenses;  Indemnification.  (a) The Borrower shall pay (i)
all  out-of-pocket  expenses  of  the  Agents,  including  reasonable  fees  and
disbursements  of  special  counsel  for the  Agents,  in  connection  with  the
preparation  and  administration  of  this  Agreement,  any  waiver  or  consent
hereunder or any amendment  hereof or any Default or alleged  Default  hereunder
and (ii) if an Event of Default occurs,  all out-of-pocket  expenses incurred by
each Agent and Bank, including (without  duplication) the fees and disbursements
of outside counsel and the allocated cost of inside counsel,  in connection with
such  Event  of  Default  and  collection,   bankruptcy,  insolvency  and  other
enforcement proceedings resulting therefrom.

     (b) The Borrower agrees to indemnify each Agent and Bank,  their respective
affiliates and the respective directors,  officers,  agents and employees of the
foregoing  (each an  "Indemnitee")  and hold each  Indemnitee  harmless from and
against any and all  liabilities,  losses,  damages,  costs and  expenses of any
kind,  including,  without limitation,  the reasonable fees and disbursements of
counsel,  which  may be  incurred  by such  Indemnitee  in  connection  with any
investigative,  administrative  or  judicial  proceeding  (whether  or not  such
Indemnitee shall be designated a party thereto)  brought or threatened  relating
to or arising out of this Agreement or any actual or proposed use of proceeds of
Loans  hereunder;  provided  that no  Indemnitee  shall  have  the  right  to be
indemnified  hereunder  for such  Indemnitee's  own gross  negligence or willful
misconduct as determined by a court of competent jurisdiction.

     SECTION 10.04.  Sharing of Set-offs.  Each Bank agrees that if it shall, by
exercising  any right of set-off or  counterclaim  or otherwise  (other than any
such right against a Shareholder Guarantor),  receive payment of a proportion of
the aggregate amount of principal and interest due with respect to any Note held
by it which is greater than the proportion received by any other Bank in respect
of the  aggregate  amount of principal and interest due with respect to any Note
held by such other Bank, the Bank receiving such proportionately greater payment
shall  purchase such  participations  in the Notes held by the other Banks,  and
such  other  adjustments  shall be  made,  as may be  required  so that all such
payments of principal  and interest  with respect to the Notes held by the Banks
shall be shared by the Banks pro rata;  provided  that  nothing in this  Section
shall  impair  the  right of any  Bank to  exercise  any  right  of  set-off  or
counterclaim it may have and to apply the amount subject to such exercise to the
payment of indebtedness  of the Borrower or the Parent  Guarantor other than its
indebtedness hereunder. Each of the Borrower and the Parent Guarantor agrees, to
the fullest  extent it may  effectively  do so under  applicable  law,  that any



                                       71




holder of a  participation  in a Note,  whether or not acquired  pursuant to the
foregoing arrangements, may exercise rights of set-off or counterclaim and other
rights  with  respect  to such  participation  as fully as if such  holder  of a
participation  were a direct creditor of the Borrower or the Parent Guarantor in
the amount of such participation.

     SECTION 10.05.  Amendments and Waivers.  Any provision of this Agreement or
the Notes may be amended or waived if, but only if, such  amendment or waiver is
in writing and is signed by the  Borrower and the  Required  Banks (and,  if the
rights or duties of an Agent are affected thereby, by such Agent); provided that
no such amendment or waiver shall,  unless signed by all the Banks, (a) increase
or decrease the  Commitment  of any Bank  (except for a ratable  decrease in the
Commitments of all Banks) or subject any Bank to any additional obligation,  (b)
reduce the principal of or rate of interest on any Loan, or any fees  hereunder,
(c)  postpone  the date fixed for any payment of principal of or interest on any
Loan, or any fees hereunder or for any scheduled reduction or termination of any
Commitment,  (d) release the Parent Guarantor from its obligations  hereunder or
the  Shareholder  Guarantors  from  their  obligations  under  the  Shareholders
Guaranties,  or (e) change the percentage of the Commitments or of the aggregate
unpaid  principal  amount of the Notes,  or the number of Banks,  which shall be
required  for the Banks or any of them to take any action  under this Section or
any other provision of this Agreement.

     SECTION 10.06. Successors and Assigns. (a) The provisions of this Agreement
shall be binding  upon and inure to the benefit of the parties  hereto and their
respective  successors  and assigns,  except that the Borrower may not assign or
otherwise  transfer  any of its rights  under this  Agreement  without the prior
written consent of all Banks.

     (b)  Any  Bank  may at  any  time  grant  to one or  more  banks  or  other
institutions (each a "Participant") participating interests in its Commitment or
any or all of  its  Loans.  In the  event  of  any  such  grant  by a Bank  of a
participating  interest  to a  Participant,  whether  or not upon  notice to the
Borrower and the Agents,  such Bank shall remain responsible for the performance
of its obligations hereunder,  and the Borrower and the Agents shall continue to
deal solely and directly  with such Bank in  connection  with such Bank's rights
and obligations under this Agreement.  Any agreement  pursuant to which any Bank
may grant  such a  participating  interest  shall  provide  that such Bank shall
retain  the sole right and  responsibility  to enforce  the  obligations  of the
Borrower  hereunder  including,  without  limitation,  the right to approve  any
amendment,  modification or waiver of any provision of this Agreement;  provided
that such  participation  agreement may provide that such Bank will not agree to
any modification, amendment or waiver of this Agreement described in clause (a),
(b),  (c), (d) or (e) of the proviso to Section 10.05 without the consent of the



                                       72




Participant.  The Borrower  agrees that each  Participant  shall,  to the extent
provided in its participation  agreement, be entitled to the benefits of Article
8 with respect to its  participating  interest.  An assignment or other transfer
which is not permitted by subsection  (c) or (d) below shall be given effect for
purposes  of this  Agreement  only to the  extent  of a  participating  interest
granted in accordance with this subsection (b).

     (c) Any Bank may at any time,  upon five Business  Days' written  notice to
each of the Agents,  assign to one or more banks or other  institutions (each an
"Assignee") all, or a proportionate part (equivalent to an initial Commitment of
not less than  $2,500,000)  of all,  of its  rights and  obligations  under this
Agreement  and the  Notes,  and such  Assignee  shall  assume  such  rights  and
obligations, pursuant to an Assignment and Assumption Agreement in substantially
the form of Exhibit D hereto executed by such Assignee and such transferor Bank,
with  (and  subject  to)  the  subscribed   consent  of  the  Borrower  and  the
Administrative  Agent,  which  consent  shall in each  case not be  unreasonably
withheld;  provided  that (x) if an Assignee is an affiliate of such  transferor
Bank or was a Bank immediately  prior to such assignment or if the Assignee is a
Shareholder Guarantor purchasing Notes pursuant to Section 1(e) of a Shareholder
Guaranty,   no  such  consent   shall  be  required  and  (y)  such  Bank  shall
contemporaneously  assign to such  Assignee an  equivalent  percentage  of loans
under the Term Credit Agreement.  Upon execution and delivery of such instrument
and payment by such Assignee to such  transferor  Bank of an amount equal to the
purchase  price agreed  between such  transferor  Bank and such  Assignee,  such
Assignee  shall be a Bank party to this  Agreement and shall have all the rights
and  obligations of a Bank with a Commitment as set forth in such  instrument of
assumption,  and the  transferor  Bank shall be  released  from its  obligations
hereunder to a  corresponding  extent,  and no further  consent or action by any
party shall be required.  Upon the  consummation  of any assignment  pursuant to
this  subsection  (c), the  transferor  Bank, the  Administrative  Agent and the
Borrower shall make appropriate arrangements so that, if required, a new Note is
issued to the Assignee,  and the  transferor  Bank shall provide  prompt written
notice of such  assignment to the  Documentation  Agent.  In connection with any
such assignment,  the transferor Bank shall pay to the  Administrative  Agent an
administrative  fee for processing such  assignment in the amount of $2,500.  If
the Assignee is not incorporated  under the laws of the United States of America
or a state  thereof,  it shall  deliver to the Borrower  and the  Administrative
Agent  certification as to exemption from deduction or withholding of any United
States federal income taxes in accordance with Section 8.04.

     (d) Any Bank may at any time assign all or any portion of its rights  under
this Agreement and its Note to a Federal Reserve Bank. No such assignment  shall
release the transferor Bank from its obligations hereunder.



                                       73





     (e) No Assignee, Participant or other transferee of any Bank's rights shall
be entitled to receive any greater  payment under Section 8.03 or 8.04 than such
Bank would have been entitled to receive with respect to the rights transferred,
unless such transfer is made with the  Borrower's  prior  written  consent or by
reason of the  provisions of Section 8.02,  8.03 or 8.04  requiring such Bank to
designate a different  Applicable Lending Office under certain  circumstances or
at a time when the  circumstances  giving rise to such  greater  payment did not
exist.

     (f) Each Bank shall, upon receipt from a Shareholder Guarantor of an amount
equal to all of such Bank's  Guaranteed  Obligations (as defined in the relevant
Shareholder  Guaranty)  (the  "Transfer  Payment"),  assign to such  Shareholder
Guarantor the  corresponding  portion of its rights and  obligations  under this
Agreement and the Notes in accordance  with paragraph (c) of this Section 10.06;
provided that (i) the consent of the Borrower and the Administrative Agent shall
not be  required  for  such  assignment  and  (ii) no such  assignment  shall be
effective until each Bank has received its Transfer  Payment from the applicable
Shareholder Guarantor.

     SECTION 10.07.  Collateral.  Each of the Banks represents to the Agents and
each of the other  Banks that it in good faith is not  relying  upon any "margin
stock"  (as  defined  in  Regulation  U)  as  collateral  in  the  extension  or
maintenance of the credit provided for in this Agreement.

     SECTION 10.08.  Governing Law;  Submission to Jurisdiction.  This Agreement
and each Note shall be governed by and construed in accordance  with the laws of
the State of New York.  Each of the  Borrower  and the Parent  Guarantor  hereby
submits to the nonexclusive jurisdiction of the United States District Court for
the Southern District of New York and of any New York State court sitting in New
York City for  purposes of all legal  proceedings  arising out of or relating to
this Agreement or the transactions contemplated hereby. Each of the Borrower and
the Parent Guarantor irrevocably waives, to the fullest extent permitted by law,
any objection  which it may now or hereafter  have to the laying of the venue of
any  such  proceeding  brought  in such a court  and any  claim  that  any  such
proceeding brought in such a court has been brought in an inconvenient forum.

     SECTION 10.09. Counterparts; Integration; Effectiveness. This Agreement may
be signed in any number of  counterparts,  each of which  shall be an  original,
with the same effect as if the signatures  thereto and hereto were upon the same
instrument.  This Agreement  constitutes the entire agreement and  understanding
among  the  parties  hereto  and  supersedes  any and all prior  agreements  and
understandings,  oral or written,  relating to the subject matter  hereof.  This



                                       74




Agreement  shall become  effective  upon receipt by the  Documentation  Agent of
counterparts hereof signed by each of the parties hereto (or, in the case of any
party as to which an executed counterpart shall not have been received,  receipt
by the  Documentation  Agent in form  satisfactory to it of telegraphic,  telex,
facsimile  or other  written  confirmation  from such  party of  execution  of a
counterpart hereof by such party).

     SECTION  10.10.  Waiver of Jury  Trial.  EACH OF THE  BORROWER,  THE PARENT
GUARANTOR,  THE AGENTS AND THE BANKS HEREBY IRREVOCABLY WAIVES ANY AND ALL RIGHT
TO TRIAL BY JURY IN ANY LEGAL  PROCEEDING  ARISING  OUT OF OR  RELATING  TO THIS
AGREEMENT OR THE TRANSACTIONS CONTEMPLATED HEREBY.

     SECTION  10.11.  Confidentiality.  Each  Bank  agrees  to take  normal  and
reasonable  precautions and exercise due care to maintain the confidentiality of
all non-public  information provided to it by the Parent Guarantor or any of its
Subsidiaries by the Agents on the Parent Guarantor's or such Subsidiary's behalf
in connection  with this Agreement or any other Loan Document and neither it nor
any of its Affiliates  shall use any such  information for any purpose or in any
manner other than pursuant to the terms  contemplated by this Agreement,  except
to the extent such  information  (a) was or becomes  generally  available to the
public other than as a result of a disclosure by the Bank, or (b) was or becomes
available  on a  non-confidential  basis  from a source  other  than the  Parent
Guarantor  or  the  Borrower,  provided  that  such  source  is not  bound  by a
confidentiality agreement with the Parent Guarantor or the Borrower known to the
Bank; provided,  further, that any Bank may disclose such information (A) to any
other Bank or to the Agents,  (B) at the request of any regulatory  authority or
in  connection  with an  examination  of such  Bank by any such  authority;  (C)
pursuant  to  subpoena or other  court  process;  (D) when  required to do so in
accordance  with  the  provisions  of any  applicable  law;  (E) at the  express
direction of any other agency of any State of the United States of America or of
any other jurisdiction in which such Bank conducts its business; and (F) to such
Bank's independent  auditors and legal counsel.  Notwithstanding  the foregoing,
the Company  authorizes  each Bank to disclose  to any  Participant  or Assignee
(each, a "Transferee")  and any prospective  Transferee such financial and other
information in such Bank's possession  concerning the Parent Guarantor or any of
its  Subsidiaries  which  has  been  delivered  to the  Banks  pursuant  to this
Agreement or which has been  delivered  to the Banks by the Parent  Guarantor or
any of its  Subsidiaries in connection with the Banks' credit  evaluation of the
Parent  Guarantor and its  Subsidiaries  prior to entering into this  Agreement;
provided  that  such  Transferee  agrees  in  writing  to such Bank to keep such
information confidential to the same extent required of the Banks hereunder.



                                       75





     IN WITNESS  WHEREOF,  the parties  hereto have caused this  Agreement to be
duly  executed by their  respective  authorized  officers as of the day and year
first above written.

 
                                   AMSC ACQUISITION COMPANY, INC.

                                   By  /s/Gary M. Parsons
                                       ------------------

                                   Name:      Gary M. Parsons
                                   Title:     Chief Executive Officer,
                                              President and Treasurer
                                   Address:   10802 Parkridge Boulevard
                                              Reston, VA 20191
                                   Attention: General Counsel
                                   Facsimile: 703-758-6134


                                   AMERICAN MOBILE SATELLITE CORPORATION

                                   By  /s/Gary M. Parsons
                                       ------------------

                                   Name:      Gary M. Parsons
                                   Title:     President and Chief
                                              Executive Officer
                                   Address:   10802 Parkridge Boulevard
                                              Reston, VA 20191
                                   Attention: General Counsel
                                   Facsimile: 703-758-6134



                                       76





                                   TORONTO DOMINION (TEXAS), INC.


                                   By  /s/Jano Mott
                                       ------------
                                   Name:      Jano Mott
                                   Title:     Vice President


                                   MORGAN GUARANTY TRUST
                                   COMPANY OF NEW YORK


                                   By  /s/John M. Mikolay
                                       ------------------
                                   Name:      John M. Mikolay
                                   Title:     Vice President


                                   BANK OF AMERICA NATIONAL
                                   TRUST AND SAVINGS
                                   ASSOCIATION


                                   By  /s/Robert W. Troutman
                                       ---------------------
                                   Name:      Robert W. Troutman
                                   Title:     Managing Director



                                       77





                                   MORGAN GUARANTY TRUST
                                   COMPANY OF NEW YORK, as
                                   Documentation Agent


                                   By  /s/John M. Mikolay
                                       ------------------

                                   Name:      John M. Mikolay
                                   Title:     Vice President
                                   Address:   500 Stanton Christiana Road
                                              Newark, DE 19713
                                   Attention: Victoria Fedale
                                   Facsimile: 302-634-1852


                                   TORONTO DOMINION (TEXAS),
                                   INC., as Administrative Agent


                                   By  /s/Jano Mott
                                       ------------

                                   Name:      Jano Mott
                                   Title:     Vice President
                                   Address:   909 Fannin Street
                                              Houston, TX 77010
                                   Attention: Jano Mott
                                   Facsimile: 713-951-9921




                                       78





                               COMMITMENT SCHEDULE




              Bank                Tranche A       Tranche B       Tranche C
                                  Commitment      Commitment      Commitment
                                                                
Toronto Dominion (Texas),        $37,500,000              $0      $6,250,000
Inc.
Morgan Guaranty Trust            $37,500,000              $0      $6,250,000
Company of New York
Bank of America National                  $0     $12,500,000              $0
Trust and Savings
Association






                                        1





                                PRICING SCHEDULE

     "Euro-Dollar  Margin" and "Commitment Fee Percentage" mean for any date the
rates set forth below in the column  corresponding  to the "Pricing  Level" that
applies at such date:





                        Level I           Level II           Level III
                                                          
Euro-Dollar Margin       0.500%             0.750%              1.000%
Commitment Fee           0.125%             0.150%              0.175%
Percentage
- ------------------     ---------          -----------        ------------



     For  purposes of this  Schedule,  the  following  terms have the  following
meanings:

     "Level  I  Pricing"  applies  at any  date  if,  as of such  date,  Hughes'
long-term debt is rated A3 or higher by Moody's and A- or higher by S&P

     "Level II  Pricing"  applies at any date if, as of such date,  (i)  Hughes'
long-term  debt is rated Baa2 or higher by Moody's  and BBB or higher by S&P and
(ii) Level I Pricing does not apply.

     "Level III  Pricing"  applies  at any date if neither  Level I nor Level II
Pricing applies.

     "Moody's" means Moody's Investors Service, Inc.

     "Pricing Level" refers to the  determination  of which of Level I, Level II
or Level III applies at any date.

     "S&P" means Standard & Poor's Rating Service.

     The credit  ratings to be utilized for purposes of this  Schedule are those
assigned to the senior  unsecured  long-term  debt  securities of Hughes without
third-party  credit  enhancement,  and any  rating  assigned  to any other  debt
security of Hughes shall be  disregarded.  The ratings in effect for any day are
those in effect at the close of business on such day.


                                        1





                               DISCLOSURE SCHEDULE


Section 1.01 -- FCC Licenses.



Section 4.03 -- Government Approvals.



Section 4.05 -- Litigation.



Section 4.07 -- Plans.



Section 4.10(c) -- Material Adverse Effect.



Section 4.13 -- Subsidiaries and Equity Investments.



Section 5.15 -- Existing Liens.



Section 5.23 -- Existing Indebtedness.








                                        1





                                                              EXHIBIT A -- Note



                                 REVOLVING NOTE

                               New York, New York
                                                              [DATE]

     For value received,  AMSC Acquisition Company, Inc., a Delaware corporation
(the "Borrower"),  promises to pay to the order of  ______________________  (the
"Bank"),  for the account of its Applicable Lending Office, the unpaid principal
amount of each Loan made by the Bank to the Borrower  pursuant to the  Revolving
Credit  Agreement  referred to below on the  maturity  date  provided for in the
Revolving Credit Agreement.  The Borrower promises to pay interest on the unpaid
principal  amount  of each  such  Loan on the  dates  and at the  rate or  rates
provided for in the Revolving Credit  Agreement.  All such payments of principal
and interest  shall be made in lawful  money of the United  States in Federal or
other immediately available funds at the office of The Toronto-Dominion Bank, 31
West 52nd Street, New York, New York.

     All Loans made by the Bank, the respective Types thereof and all repayments
of the  principal  thereof  shall be  recorded  by the Bank and,  if the Bank so
elects in  connection  with any  transfer  or  enforcement  hereof,  appropriate
notations to evidence the foregoing  information  with respect to each such Loan
then outstanding may be endorsed by the Bank on the schedule attached hereto, or
on a continuation of such schedule attached to and made a part hereof;  provided
that the failure of the Bank to make any such  recordation or endorsement  shall
not affect the  obligations  of the Borrower  hereunder  or under the  Revolving
Credit Agreement.

     This note is one of the Notes referred to in the Revolving Credit Agreement
dated as of March 31, 1998 among AMSC Acquisition Company, Inc., American Mobile
Satellite Corporation, the banks party thereto, Morgan Guaranty Trust Company of
New  York,  as  Documentation  Agent  and  Toronto  Dominion  (Texas),  Inc.  as
Administrative  Agent  (as the  same  may be  amended  from  time to  time,  the
"Revolving Credit  Agreement").  Terms defined in the Revolving Credit Agreement
are used  herein  with the same  meanings.  Reference  is made to the  Revolving
Credit  Agreement for provisions for the prepayment  hereof and the acceleration
of the maturity hereof.


                                        1





     The  payment  in full of the  principal  and  interest  on this  note  has,
pursuant  to  the   provisions  of  the   Revolving   Credit   Agreement,   been
unconditionally guaranteed by American Mobile Satellite Corporation.

                                 AMSC ACQUISITION COMPANY, INC.



                                 By --------------------------------------------

                                 Name:
                                 Title:



                                        2






                         LOANS AND PAYMENTS OF PRINCIPAL

- --------------------------------------------------------------------------
           Amount           Type        Amount of
               of             of        Principal            Notation
Date         Loan           Loan          Repaid              Made By
- --------------------------------------------------------------------------

- --------------------------------------------------------------------------

- --------------------------------------------------------------------------

- --------------------------------------------------------------------------

- --------------------------------------------------------------------------

- --------------------------------------------------------------------------

- --------------------------------------------------------------------------

- --------------------------------------------------------------------------

- --------------------------------------------------------------------------

- --------------------------------------------------------------------------

- --------------------------------------------------------------------------

- --------------------------------------------------------------------------

- --------------------------------------------------------------------------

- --------------------------------------------------------------------------

- --------------------------------------------------------------------------

- --------------------------------------------------------------------------

- --------------------------------------------------------------------------

- --------------------------------------------------------------------------



                                        3





                EXHIBIT B -- Opinion of Counsel for the Borrower
                            and the Parent Guarantor

                                   OPINION OF
                            COUNSEL FOR THE BORROWER
                            AND THE PARENT GUARANTOR



                                                  March __, 1998


To the Banks, Shareholder Guarantors and the Agents
Referred to Below
c/o Morgan Guaranty Trust Company
of New York, as Documentation Agent
60 Wall Street
New York, New York  10260

Dear Sirs:

         I am Vice President,  Secretary and General Counsel of AMSC Acquisition
Company,  Inc., a Delaware corporation (the "Acquisition"),  and American Mobile
Satellite  corporation,  a Delaware Corporation (the "AMSC"). In such capacity I
have become  familiar with the  $100,000,000  Revolving  Credit  Agreement  (the
"Revolving Credit Agreement") among  Acquisition,  AMSC, the banks listed on the
signature  pages  thereof,  Morgan  Guaranty  Trust  Company  of  New  York,  as
Documentation Agent and Toronto Dominion (Texas),  Inc. as Administrative Agent.
Capitalized terms not otherwise defined herein shall have the meanings set forth
in the  Revolving  Credit  Agreement.  This  opinion  is being  rendered  to you
pursuant to Section 3.01 of the Revolving Credit Agreement.

         In rendering this opinion, I have examined originals or copies of:

1.       the Revolving Credit Agreement, the Notes and each Subsidiary
         Guaranty (collectively, the "Loan Documents");

2.       the certificates of incorporation, as amended, of AMSC, Acquisition and
         each Subsidiary of Acquisition (collectively, the "Loan Parties");

3.       the bylaws, as amended, of each Loan Party;



                                        1





4.       the  Certificates  of Good  Standing  with  respect  to each Loan Party
         issued by the  Secretary  of State of the State of Delaware not earlier
         than March 20, 1998;

5.       the Certificate of Good Standing as a Foreign  Corporation with respect
         to AMSC issued by the State Corporation  Commission of the Commonwealth
         of Virginia dated March __, 1998;

6.       certain  resolutions  adopted  by the Board of  Directors  of AMSC at a
         meeting of the Board held on March 19, 1998;

7.       certain  resolutions  adopted by unanimous written consent of the Board
         of Directors of Acquisition dated March 19, 1998; and

8.       certain   resolutions  adopted  by  the  Board  of  Directors  of  each
         Subsidiary of  Acquisition at meetings of such Boards held on March 19,
         1998;

upon all of which I have relied. I have not  independently  verified any factual
matters in connection with or apart from my review of the documents  referred to
above and,  accordingly,  I do not express any opinion as to matters  that might
have been disclosed by independent verification.

         In arriving at the opinions  expressed  below, I have assumed,  and not
verified, the authenticity of all documents submitted to me as originals and the
conformity to original documents of all documents  submitted to me as copies, as
well as the due and valid  authorization,  execution  and  delivery  of all such
documents by the appropriate party or parties (other than the Loan Parties), and
that each such party  (other than the  applicable  Loan  Parties)  has  adequate
power,  authority and legal right to enter into such  documents to which it is a
party and to  perform  its  obligations  under such  documents  to which it is a
party.

         Based solely upon the foregoing and in reliance thereon, and subject to
the  qualifications,  limitations  and  assumptions  set forth herein,  it is my
opinion that:

         1. Each Loan Party is a corporation duly incorporated, validly existing
and in good  standing  under  the  laws of  Delaware  and,  in the  case of AMSC
Subsidiary Corporation, under the laws of Virginia, has all corporate powers and
all material  governmental  licenses,  authorizations,  consents  and  approvals
required to carry on its business as now  conducted,  and is duly qualified as a
foreign  corporation,  licensed  and in good  standing  under  the  laws of each
jurisdiction where its ownership,  lease or operation of property or the conduct
of its  business  require such  qualification  except where the failure to be so



                                        2





qualified  would not  reasonably  be  expected  to result in a Material  Adverse
Effect.

         2. The  execution,  delivery and  performance  by AMSC of the Revolving
Credit Agreement, by Acquisition of the Revolving Credit Agreement and the Notes
and by each  Subsidiary of Acquisition  of the Subsidiary  Guaranties are within
the corporate powers of AMSC, Acquisition or such Subsidiary,  as relevant, have
been duly authorized by all necessary  corporate action and do not and will not:
(a) contravene the terms of such Person's  certificate of incorporation,  bylaws
or other  organization  documents;  (b) conflict with or result in any breach or
contravention  of, or the creation of any Lien under, any indenture,  agreement,
lease,  instrument,   Contractual  Obligation,   injunction,  order,  decree  or
undertaking to which such Person is a party;  or (c) violate any  Requirement of
Law.

         3.  Each  Loan  Document  constitutes  the  legal,  valid  and  binding
obligations or agreements of each Loan Party party thereto,  enforceable against
such Loan Party in accordance with its terms.

         4. Except as set forth in Section 4.05 of the  Disclosure  Schedule and
for matters  arising  after the  Effective  Date which could not  reasonably  be
expected  to have a  Material  Adverse  Effect,  there  are no  actions,  suits,
proceedings,  claims  or  disputes  pending,  or to the  best of our  knowledge,
threatened  or  contemplated  at law, in equity,  in  arbitration  or before any
Governmental Authority,  against AMSC or any of its Subsidiaries or any of their
respective  properties  which:  (a)  purport  to affect or  pertain  to any Loan
Document, or any of the transactions  contemplated thereby; or (b) if determined
adversely  to AMSC or any of its  Subsidiaries,  could have a  Material  Adverse
Effect.  No injunction,  writ,  temporary  restraining order or any order of any
nature has been issued by any court or other Governmental  Authority  purporting
to enjoin or  restrain  the  execution,  delivery  and  performance  of any Loan
Document,  or  directing  that the  transactions  provided  for  therein  not be
consummated as therein provided.

         5.  None of  AMSC,  any  Person  controlling  AMSC,  or any  Subsidiary
thereof,  is (a) an  "Investment  Company"  within the meaning of the Investment
Company  Act of 1940;  or (b)  subject to  regulation  under the Public  Utility
Holding Company Act of 1935, or, to the best of our knowledge, the Federal Power
Act, the Interstate  Commerce Act, any state public  utilities code or any other
Federal  or  state  statute  or   regulation   limiting  its  ability  to  incur
Indebtedness.



                                        3





         The  foregoing  opinions are subject to the following  assumptions  and
qualifications:

         (a) The  opinions set forth in paragraph 3 are subject to the effect of
any applicable  bankruptcy,  insolvency,  reorganization,  moratorium or similar
laws  affecting  creditors'  rights  generally  and  to  the  possible  judicial
application of foreign laws or governmental  action affecting the enforcement of
creditors' rights.

         (b) The  opinions  set forth in  paragraph 3 are subject to the further
qualification  that the  enforceability  of the  obligations of the Loan Parties
under Loan Documents are subject to general  principles of equity (regardless of
whether such  enforceability is considered in a proceeding in equity or at law).
Such  principles  of equity are of general  application  and, in  applying  such
principles,  a  court,  among  other  things,  might  not  allow a  creditor  to
accelerate  the  maturity  of a debt upon the  occurrence  of a  default  deemed
immaterial  or might  decline  to  order  that a  covenant  be  performed.  Such
principles  applied by a court might include,  among other things, a requirement
that creditors act with  reasonableness and good faith. Such a requirement might
be applied,  among other  situations,  to the  provisions  of any Loan  Document
requiring  the payment of an indemnity or  compensation  to any party thereto or
purporting to authorize conclusive determinations by any party thereto.

         (c) Without  limiting the foregoing,  I call to your attention  certain
exceptions noted below.

                  (i) With  respect  to my  opinion  in  paragraph  3 hereof,  I
         express no opinion as to  whether  the courts of a  jurisdiction  other
         than the State of New York would give  effect to the choice of New York
         law as  governing  the  agreements  as to which I express an opinion in
         paragraph 3.

                  (ii) I express no opinion as to the possible  applicability to
         transactions  contemplated  by the Loan Documents of Section 548 of the
         United  States  Bankruptcy  Code  or  comparable  provisions  of  other
         applicable law.

                  (iii) With respect to my opinion in paragraph 3 hereof,

                         (A)  No  opinion  is  expressed  with  respect  to  the
                    enforceability   of  any  provision  in  Article  9  of  the
                    Revolving  Credit  Agreement or Section 5 of each Subsidiary
                    Guaranty  purporting to guarantee a liability of Acquisition





                                        4



                    despite the fact that the obligations  being  guaranteed are
                    unenforceable  due to illegality or the fact that any one of
                    the Agents or any one of the Banks had voluntarily  released
                    Acquisition's  liability  with  respect  to such  guaranteed
                    obligations.

                         (B)  Section  9.02(a) and (b) of the  Revolving  Credit
                    Agreement  and  Section  5(a) of each  Subsidiary  Guaranty,
                    which  provide that the liability of AMSC or a Subsidiary of
                    Acquisition  shall  not  be  affected  by  certain  changes,
                    modifications,  amendments  or waivers  referred to therein,
                    might be  enforceable  only to the extent that such changes,
                    modifications, amendments or waivers were not so material as
                    to constitute a new contract among the parties.

                         (C) I express no opinion  as to the  enforceability  of
                    Section 9.04 of the Revolving  Credit Agreement or Section 6
                    of each Subsidiary Guaranty insofar as either of them relate
                    to any waiver or extension of or agreement not to assert any
                    defense based upon an applicable statue of limitations.

     (d) The  foregoing  opinions  are  limited  to the laws of the State of New
York,  the General  Corporation  Law of the State of  Delaware,  the laws of the
Commonwealth  of Virginia  and the Federal law of the United  States  (except as
noted below),  and I do not express any opinion herein  concerning any other law
(including,  without limitation,  any such other law of any jurisdiction wherein
any party to any of Loan  Document  may be located or deemed  located or wherein
enforcement of any such  documents may be sought).  I do not express any opinion
as to any matters arising under the Communications  Act of 1934, as amended,  or
any rules or  regulations  of the Federal  Communications  Commission.  I do not
express  any  opinion  as to  any  matters  (including  Governmental  Approvals)
relating  to  international  law,  including  compliance  by any Loan Party with
treaties  involving  the  International  Maritime  Satellite  Organization,  the
International  Telecommunications  Satellite  Organization and the International
Telecommunication  Union.  I am not a member of the Bar of the State of Delaware
and insofar as the opinions  expressed  herein  relate to matters of the General
Corporation  Law of the State of Delaware,  I have relied on the latest standard
compilations of statutes available to me.

     The  opinions  herein are  rendered as of the date of this  opinion,  and I
assume no obligation to revise or supplement this opinion at any date subsequent
hereto.


                                        5





     The opinions  set forth above  relate  solely to the matters as to which my
opinion  has been  requested  by you,  and you must judge  whether  the  matters
addressed herein are sufficient for your purposes.  I do not express any opinion
as to any other matters.

     This opinion is rendered to the  Documentation  Agent and is solely for its
benefit, for the benefit of the Shareholder  Guarantors,  and for the benefit of
any Bank party to the Revolving  Credit  Agreement in connection  with the above
transaction.  This opinion may not be relied upon by the Documentation Agent for
any other purpose, or furnished to, quoted to or relied upon by any other Person
other than any Bank or  Shareholder  Guarantor  referred  to in the  immediately
preceding sentence,  for any purpose without my prior written consent. It is not
to be filed with or furnished to any  Governmental  Authority or other Person in
either case without my prior written consent.

                                            Very truly yours,


                                            /s/Randy S. Segal
                                            Randy S. Segal
                                            General Counsel


                                        6





             EXHIBIT C -- Opinion of Special Counsel for the Agents


                                   OPINION OF
                             DAVIS POLK & WARDWELL,
                         SPECIAL COUNSEL FOR THE AGENTS


                                                        March __, 1998


To the Banks and the Agents
Referred to Below
c/o Morgan Guaranty Trust Company
of New York, as Documentation Agent
60 Wall Street
New York, New York  10260

Dear Sirs:

         We have  participated in the preparation of the $100,000,000  Revolving
Credit Agreement (the "Revolving  Credit  Agreement") dated as of March 31, 1998
among AMSC Acquisition Company,  Inc., a Delaware  corporation  ("Acquisition"),
American Mobile Satellite  Corporation,  a Delaware  corporation  ("AMSC"),  the
banks listed on the signature pages thereof (the "Banks"), Morgan Guaranty Trust
Company of New York, as Documentation Agent, and Toronto Dominion (Texas), Inc.,
as Administrative Agent (collectively,  the "Agents"), and have acted as special
counsel for the Agents for the purpose of  rendering  this  opinion  pursuant to
Section 3.01 of the Revolving Credit  Agreement.  Terms defined in the Revolving
Credit Agreement are used herein as therein defined.

         We have examined originals or copies, certified or otherwise identified
to our  satisfaction,  of such  documents,  corporate  records,  certificates of
public   officials  and  other   instruments   and  have  conducted  such  other
investigations  of fact and law as we have deemed  necessary  or  advisable  for
purposes of this opinion.

         Upon the basis of the  foregoing,  we are of the opinion that  assuming
that the  execution,  delivery and  performance  by Acquisition of the Revolving
Credit Agreement and the Notes and by AMSC of the Revolving Credit Agreement are
within  such  Person's  corporate  powers and have been duly  authorized  by all
necessary  corporate action, the Revolving Credit Agreement  constitutes a valid




                                        1




and binding  agreement of Acquisition and AMSC and each Note constitutes a valid
and binding  obligation of Acquisition,  in each case  enforceable in accordance
with its terms  except as may be limited by  bankruptcy,  insolvency  or similar
laws affecting creditors' rights generally and by general principles of equity.

         We are  members  of the Bar of the State of New York and the  foregoing
opinion is limited to the laws of the State of New York. In giving the foregoing
opinion,  we  express  no  opinion  as to the  effect (if any) of any law of any
jurisdiction  (except the State of New York) in which any Bank is located  which
limits the rate of interest that such Bank may charge or collect.

         This  opinion is rendered  solely to you in  connection  with the above
matter.  This  opinion  may not be relied  upon by you for any other  purpose or
relied upon by any other person without our prior written consent.

                                            Very truly yours,



                                        2





                EXHIBIT D -- Assignment and Assumption Agreement



                       ASSIGNMENT AND ASSUMPTION AGREEMENT

         AGREEMENT  dated as of  _________,  19__ among [NAME OF ASSIGNOR]  (the
"Assignor"), [NAME OF ASSIGNEE] (the "Assignee"), AMSC ACQUISITION COMPANY, INC.
(the "Borrower") and TORONTO DOMINION  (TEXAS),  INC., as  Administrative  Agent
(the "Agent").

         WHEREAS,  this  Assignment and Assumption  Agreement (the  "Agreement")
relates to the  $100,000,000  Revolving  Credit  Agreement dated as of March 31,
1998  among the  Borrower,  American  Mobile  Satellite  Corporation,  as Parent
Guarantor,  the Assignor  and the other Banks party  thereto,  as Banks,  Morgan
Guaranty Trust Company of New York, as  Documentation  Agent, and the Agent (the
"Credit Agreement");

         WHEREAS,  as provided  under the Credit  Agreement,  the Assignor has a
Commitment to make Loans to the Borrower in an aggregate principal amount at any
time outstanding not to exceed $__________;*

         WHEREAS,  Loans made to the Borrower by the  Assignor  under the Credit
Agreement in the aggregate  principal  amount of $__________  are outstanding at
the date hereof; and

         WHEREAS,  the  Assignor  proposes to assign to the  Assignee all of the
rights of the Assignor under the Credit Agreement in respect of a portion of its
Commitment thereunder in an amount equal to $__________ (the "Assigned Amount"),
together with a corresponding portion of its outstanding Loans, and the Assignee
proposes  to accept  assignment  of such  rights and  assume  the  corresponding
obligations from the Assignor on such terms;

         NOW,  THEREFORE,  in  consideration  of the  foregoing  and the  mutual
agreements contained herein, the parties hereto agree as follows:

         1.  Definitions.  All  capitalized  terms  not otherwise defined herein
shall have the respective meanings set forth in the Credit Agreement.

- --------
        1 To be modified if assignment occurs after Commitments have terminated.



                                        1





         2.  Assignment.  The Assignor  hereby assigns and sells to the Assignee
all of the rights of the  Assignor  under the Credit  Agreement to the extent of
the Assigned  Amount,  and the Assignee  hereby accepts such assignment from the
Assignor and assumes all of the  obligations  of the  Assignor  under the Credit
Agreement to the extent of the Assigned Amount,  including the purchase from the
Assignor of the corresponding  portion of the principal amount of the Loans made
by the Assignor  outstanding at the date hereof. Upon the execution and delivery
hereof by the  Assignor,  the  Assignee,  [the  Borrower  and the Agent] and the
payment of the  amounts  specified  in Section 3 required to be paid on the date
hereof (i) the Assignee shall, as of the date hereof,  succeed to the rights and
be obligated  to perform the  obligations  of a Bank under the Credit  Agreement
with a  Commitment  in an  amount  equal to the  Assigned  Amount,  and (ii) the
Commitment of the Assignor  shall,  as of the date hereof,  be reduced by a like
amount and the Assignor released from its obligations under the Credit Agreement
to the extent such obligations have been assumed by the Assignee. The assignment
provided for herein shall be without recourse to the Assignor.

         3. Payments.  As consideration for the assignment and sale contemplated
in Section 2 hereof,  the Assignee  shall pay to the Assignor on the date hereof
in Federal funds the amount  heretofore  agreed  between them.* It is understood
that  commitment  and/or  facility  fees  accrued to the date hereof are for the
account of the  Assignor  and such fees  accruing  from and  including  the date
hereof  are for the  account  of the  Assignee.  Each  of the  Assignor  and the
Assignee hereby agrees that if it receives any amount under the Credit Agreement
which is for the account of the other party  hereto,  it shall  receive the same
for the account of such other party to the extent of such other party's interest
therein and shall promptly pay the same to such other party.

         [4.  Consent  of  the  Borrower  and  the  Agent.   This  Agreement  is
conditioned  upon the consent of the Borrower and the Agents pursuant to Section
10.06 of the Credit  Agreement.  The execution of this Agreement by the Borrower
and the Agents is  evidence  of this  consent.  Pursuant  to Section  2.03,  the
Borrower  agrees  to  execute  and  deliver a Note  payable  to the order of the
Assignee to evidence the assignment and assumption provided for herein.]

         5.  Non-Reliance on Assignor.  The Assignor makes no  representation or
warranty in connection with, and shall have no  responsibility  with respect to,
the  solvency, financial  condition, or statements of the Borrower or the Parent

- --------
         1 Amount should combine  principal  together with accrued  interest and
breakage compensation, if any, to be paid by the Assignee, net of any portion of
any upfront fee to be paid by the Assignor to the Assignee. It may be preferable
in an appropriate case to specify these amounts generically or by formula rather
than as a fixed sum.



                                        2





Guarantor, or the validity and enforceability of the obligations of the Borrower
or the Parent  Guarantor  in respect of the Credit  Agreement  or any Note.  The
Assignee  acknowledges  that it has,  independently  and without reliance on the
Assignor,  and  based  on  such  documents  and  information  as it  has  deemed
appropriate,  made its own  credit  analysis  and  decision  to enter  into this
Agreement and will  continue to be  responsible  for making its own  independent
appraisal of the business, affairs and financial condition of the Borrower.

         6. Governing Law. This Agreement  shall be governed by and construed in
accordance with the laws of the State of New York.

         7.  Counterparts.  This  Agreement  may  be  signed  in any  number  of
counterparts, each of which shall be an original, with the same effect as if the
signatures thereto and hereto were upon the same instrument.

         IN WITNESS  WHEREOF,  the  parties  have caused  this  Agreement  to be
executed and  delivered by their duly  authorized  officers as of the date first
above written.

                                  [NAME OF ASSIGNOR]


                                  By -------------------------------------------

                                  Name:
                                  Title:


                                  [NAME OF ASSIGNEE]


                                  By -------------------------------------------

                                  Name:
                                  Title:


                                  AMSC ACQUISITION COMPANY, INC.


                                  By -------------------------------------------

                                  Name:
                                  Title:





                                        3





                                   TORONTO DOMINION (TEXAS), INC.,
                                   as Administrative Agent


                                   By ------------------------------------------

                                   Name:
                                   Title:




                                        4





                         EXHIBIT E - Subsidiary Guaranty


                               SUBSIDIARY GUARANTY


TO:  Toronto Dominion (Texas), Inc.,
     as Administrative Agent


                             PRELIMINARY STATEMENTS:

         A.  AMSC  Acquisition  Company,   Inc.,  a  Delaware  corporation  (the
"Borrower"),  the Banks named  therein  (the  "Banks"),  Morgan  Guaranty  Trust
Company of New York, as Documentation Agent and Toronto Dominion (Texas),  Inc.,
as Administrative Agent (the "Agent"),  are parties to a $100,000,000  Revolving
Credit Agreement dated as of March 31, 1998 (said agreement, as it may hereafter
be amended,  supplemented,  restated or otherwise modified from time to time, is
referred to herein as the "Revolving Credit Agreement").

         B. The  undersigned  Guarantor  ("Guarantor")  is a  Subsidiary  of the
Borrower and it is a requirement  of the  Revolving  Credit  Agreement  that the
Guarantor enter into this Guaranty  guaranteeing all obligations of every nature
of the  Borrower  from time to time owed under or in  respect  of the  Revolving
Credit Agreement and the other Loan Documents (the "Guarantied Obligations").

         NOW, THEREFORE, the Guarantor agrees as follows:

         1.   For   valuable    consideration,    the   undersigned    Guarantor
unconditionally,  absolutely and  irrevocably  guarantees and promises to pay to
the Agent,  or order,  on  demand,  when due  (whether  by  scheduled  maturity,
required prepayment,  acceleration, demand, or otherwise) in lawful money of the
United States and in immediately  available funds, any and all present or future
Guarantied  Obligations  owing to the  Agents and the Banks  (collectively,  the
"Guarantied  Parties").  The term  Guarantied  Obligations is used herein in its
most comprehensive sense and include any and all advances,  debts,  obligations,
and liabilities of the Borrower,  now, or hereafter made, incurred,  or created,
whether  voluntary or  involuntarily,  and however arising,  including,  without
limitation,  any and all attorneys' fees, costs, premiums,  charges, or interest
owed by the Borrower to the Guarantied Parties, whether due or not due, absolute
or contingent, liquidated or unliquidated,  determined or undetermined,  whether
the Borrower may be liable individually or jointly with others, whether recovery




                                        1




upon such  indebtedness  may be or  hereafter  becomes  barred by any statute of
limitations or whether such  indebtedness  may be or hereafter  become otherwise
unenforceable.

         2. Notwithstanding the foregoing, the liability of Guarantor under this
guaranty  shall be limited to an aggregate  amount  equal to the largest  amount
that would not render  its  obligations  hereunder  subject to  avoidance  under
Section 548 of the United States Bankruptcy Code or any comparable provisions of
any applicable state law.

         3.  This  Guaranty  is a  continuing  guaranty  which  relates  to  any
Guarantied Obligation, including those which arise under successive transactions
which  shall  either  cause the  Borrower to incur new  Guarantied  Obligations,
continue the Guarantied  Obligations from time to time, or renew them after they
have been  satisfied.  The  Guarantor  agrees that  nothing  shall  discharge or
satisfy its obligations created hereunder except for the full payment in cash of
the Guarantied Obligations with interest as applicable.

         4. The Guarantor agrees that it is directly liable to the Agent for the
benefit of the Guarantied  Parties for payment of the Guarantied  Obligations if
the Borrower  has failed to make payment  thereof when due (whether by scheduled
maturity,  required prepayment,  acceleration,  demand, or otherwise),  that its
obligations  hereunder are  independent  of the  Guarantied  Obligations  of the
Borrower,  or of any other guarantor,  and that a separate action or actions may
be brought and  prosecuted  against  the  Guarantor,  whether  action is brought
against the  Borrower  or whether  the  Borrower is joined in any such action or
actions.  The  Guarantor  agrees  that any  releases  which  may be given by the
Guarantied  Parties to the Borrower or any other  guarantor shall not release it
from this Guaranty.

         5. The  obligations  of the Guarantor  under this Guaranty shall not be
affected,  modified or impaired upon the occurrence  from time to time of any of
the following, whether or not with notice to or the consent of the Guarantor:

         (a)      the compromise, settlement, change, modification, amendment
(whether material or otherwise) or partial termination of any or all of the
Guarantied Obligations;

         (b) the failure to give notice to the  Guarantor of the  occurrence  of
any Event of Default under the terms and provisions of the Agreement;

         (c)      the waiver of the payment, performance or observance of any of
the Guarantied Obligations;



                                        2





         (d) the taking or omitting  to take any  actions  referred to in any of
the Loan Documents or of any action under this Guaranty;

         (e) any  failure,  omission  or  delay  on the  part of the  Guarantied
Parties to enforce,  assert or exercise any right,  power or remedy conferred in
this Guaranty,  the Revolving Credit  Agreement,  any other Loan Document or any
other  indulgence or similar act on the part of the  Guarantied  Parties in good
faith and in compliance with applicable law;

         (f) the  voluntary or  involuntary  liquidation,  dissolution,  sale or
other  disposition  of all or  substantially  all of the assets,  marshalling of
assets,  receivership,  insolvency,  bankruptcy,  assignment  for the benefit of
creditors or  readjustment  of, or other  similar  proceedings  which affect the
Guarantor,  any other  guarantor  of any of the  Guarantied  Obligations  of the
Borrower or any of the assets of any of them, or any allegation of invalidity or
contest of the validity of this Guaranty in any such proceeding;

         (g) to the extent  permitted  by law,  the release or  discharge of any
other  guarantors  of  the  Guarantied   Obligations  from  the  performance  or
observance of any obligation,  covenant or agreement contained in any guaranties
of the Guarantied Obligations by operation of law; or

         (h) the default or failure of any other  guarantors  of the  Guarantied
Obligations  fully to perform any of their  respective  obligations set forth in
any such guaranties of the Guarantied Obligations.

         To the  extent any of the  foregoing  refers to any  actions  which the
Guarantied  Parties may take,  the Guarantor  hereby agrees that the  Guarantied
Parties may take such actions in such manner, upon such terms, and at such times
as the Guarantied Parties, in their discretion, deem advisable,  without, in any
way or respect, impairing,  affecting,  reducing or releasing the Guarantor from
its undertakings  hereunder and the Guarantor hereby consents to each and all of
the foregoing actions, events and occurrences.

         6. The Guarantor hereby waives:

         (a) any and all rights to require the  Guarantied  Parties to prosecute
or seek to enforce any  remedies  against the Borrower or any other party liable
to the Guarantied Parties on account of the Guarantied Obligations;

         (b) any right to assert  against  the  Guarantied  Parties any legal or
equitable  defense  (other than  indefeasible  payment in full of the Guarantied
Obligations or as expressly provided in this Guaranty),  set-off,  counterclaim,




                                        3





or claim which the Guarantor may now or at any time  hereafter  have against the
Borrower  or any other  party  liable to the  Guarantied  Parties  in any way or
manner under the Revolving Credit Agreement;

         (c) all  defenses,  counterclaims  and  off-sets of any kind or nature,
arising  directly or indirectly  from the present or future lack of  perfection,
sufficiency,  validity or  enforceability  of any Loan Document and the security
interest granted pursuant thereto;

         (d) any defense arising by reason of any claim or defense based upon an
election of remedies by the Guarantied  Parties including,  without  limitation,
any direction to proceed by judicial or  nonjudicial  foreclosure  or by deed in
lieu thereof, which, in any manner impairs, affects, reduces, releases, destroys
or extinguishes the Guarantor's  subrogation  rights,  rights to proceed against
the Borrower for reimbursement,  or any other rights of the Guarantor to proceed
against  the  Borrower,  against  any  other  guarantor,  or  against  any other
security,  with the Guarantor  understanding that the exercise by the Guarantied
Parties of certain  rights and remedies may offset or eliminate the  Guarantor's
right of subrogation against the Borrower,  and that the Guarantor may therefore
incur partially or totally non-reimbursable liability hereunder; and

         (e)   all   presentments,   demands   for   performance,   notices   of
non-performance,  protests,  notices of protest, notices of dishonor, notices of
default,  notice of acceptance of this  Guaranty,  and notices of the existence,
creation, or incurring of new or additional indebtedness,  and all other notices
or formalities to which the Guarantor may be entitled.

         7. The  Guarantor  hereby  agrees that unless and until all  Guarantied
Obligations have been paid to the Guarantied  Parties in full, it shall not have
any rights of subrogation, reimbursement or contribution as against the Borrower
or any other  guarantor,  if any,  and shall not seek to assert or  enforce  the
same. The Guarantor  understands that the exercise by the Guarantied  Parties of
certain  rights  and  remedies  contained  in the Loan  Documents  may affect or
eliminate the Guarantor's  right of subrogation if any, against the Borrower and
that the Guarantor may therefore  incur a partially or totally  non-reimbursable
liability hereunder;  nevertheless, the Guarantor hereby authorizes and empowers
the  Guarantied  Parties to exercise,  in their sole  discretion,  any right and
remedy, or any combination thereof, which may then be available, since it is the
intent and purpose of the  Guarantor  that the  obligations  hereunder  shall be
absolute, independent and unconditional under any and all circumstances.

         8. The Guarantor is presently  informed of the  financial  condition of
the  Borrower  and of all other  circumstances  which a diligent  inquiry  would




                                        4





reveal and which bear upon the risk of nonpayment of the Guarantied Obligations.
The Guarantor  hereby covenants that it will continue to keep itself informed of
the financial condition of the Borrower, the status of other guarantors, if any,
and of all  other  circumstances  which  bear upon the risk of  nonpayment.  The
Guarantor hereby waives its right, if any, to require the Guarantied  Parties to
disclose  to it  any  information  which  they  may  now  or  hereafter  acquire
concerning such condition or  circumstances  including,  but not limited to, the
release of any other guarantor.

         9. The Guarantied  Parties' books and records evidencing the Guarantied
Obligations shall be admissible in any action or proceeding and shall be binding
upon the Guarantor for the purpose of  establishing  the terms set forth therein
and shall constitute prima facie proof thereof.

         10. The  Guarantor  represents  and  warrants  for and with  respect to
itself that:

         (a) The Guarantor is a corporation  duly  organized and existing  under
the laws of the state of , and is properly licensed and in good standing in, and
where  necessary to maintain its rights and  privileges  have  complied with the
fictitious  name statute of, every  jurisdiction  in which it is doing business,
except  where the failure to be  licensed or be in good  standing or comply with
any such statute will not have a material  adverse  effect on the ability of the
Guarantor  to perform  its  obligations  hereunder  or under any  instrument  or
agreement required hereunder;

         (b) The  execution,  delivery and  performance of this Guaranty and any
instrument  or  agreement  required  hereunder  are  within  the  power  of  the
Guarantor,  have been duly authorized by, and are not in conflict with the terms
of any charter, by-law or other organization papers of, the Guarantor;

         (c) No approval, consent, exemption or other action by, or notice to or
filing with,  any  governmental  authority is necessary in  connection  with the
execution,  delivery,  performance  or  enforcement  of  this  Guaranty  or  any
instrument or agreement required hereunder, except as may have been obtained and
certified  copies of which  have  been  delivered  to Agent  and the  Guarantied
Parties;

         (d) There is no law,  rule or  regulation,  nor is there any  judgment,
decree or order of any court or governmental authority binding on the Guarantor,
which  would  be  contravened  by  the  execution,   delivery,   performance  or
enforcement of this Guaranty or any instrument or agreement required hereunder;


                                        5





         (e) This  Guaranty  is a legal,  valid  and  binding  agreement  of the
Guarantor,  enforceable  against the Guarantor in accordance with its terms, and
any  instrument or agreement  required  hereunder,  when executed and delivered,
will  be  similarly  legal,  valid,   binding  and  enforceable,   except  where
enforceability  thereof may be limited by applicable law relating to bankruptcy,
insolvency,  moratorium  or  other  similar  laws  affecting  creditors'  rights
generally or by the application of general principles of equity;

         (f) There is no action,  suit or proceeding pending against,  or to the
knowledge  of the  Guarantor,  threatened  against or affecting  the  Guarantor,
before any court or  arbitrator  or any  governmental  body,  agency or official
which in any manner draws into question that validity or  enforceability of this
Guaranty; and

         (g) The  execution,  delivery and  performance by the Guarantor of this
Guaranty  does  not  constitute,  to the  best  knowledge  of the  Guarantor,  a
"fraudulent conveyance," "fraudulent obligation" or "fraudulent transfer" within
the meanings of the Uniform  Fraudulent  Conveyances  Act or Uniform  Fraudulent
Transfer Act, as enacted in any jurisdiction.

         11. Any one of the following events shall constitute a "Guarantor Event
of Default:"

         (a) The  Guarantor  is  generally  not paying or admits in writing  its
inability  to pay its debts as such debts  become due, or files any  petition or
action  for  relief  under  any  bankruptcy,   reorganization,   insolvency,  or
moratorium law or any other law for the relief of, or relating to, debtors,  now
or hereafter in effect, or makes any assignment for the benefit of creditors, or
takes any corporate action in furtherance of any of the foregoing;

         (b) An  involuntary  petition is filed against the Guarantor  under any
bankruptcy  statute  now or  hereafter  in  effect,  or a  custodian,  receiver,
trustee,  assignee for the benefit of creditors (or other  similar  official) is
appointed  to  take  possession,  custody  or  control  of any  property  of the
Guarantor,  unless such  petition or  appointment  is set aside or  withdrawn or
ceases to be in effect  within  sixty (60) days from the date of said  filing or
appointment.

THEN,  any and all of the  Guarantor's  obligations  under this  Guaranty  shall
become due,  payable and  enforceable  against the Guarantor  whether or not the
Guarantied  Obligations  are then due and payable without  presentment,  demand,
protest or other  requirements  of any kind,  all of which are hereby  expressly
waived by the Guarantor,  and the obligation of each Bank to make any Loan under
the Revolving Credit Agreement shall thereupon terminate.



                                        6





         12. This Guaranty  shall be binding upon the  successors and assigns of
the  Guarantor  and  shall  inure  to the  benefit  of the  Guarantied  Parties'
successors  and  assigns.  This  Guaranty  cannot be assigned  by the  Guarantor
without the prior written  consents of the Guarantied  Parties which shall be in
the Guarantied Parties' sole and absolute discretion.

         13. No failure or delay by the  Guarantied  Parties in  exercising  any
right, power or privilege  hereunder shall operate as a waiver thereof nor shall
any single or partial  exercise  thereof  preclude any other or further exercise
thereof or the exercise of any other right,  power or privilege.  The rights and
remedies  herein provided shall be cumulative and not exclusive of any rights or
remedies provided by law.

         14. The Guarantor shall pay all out-of-pocket  expenses incurred by the
Agent and the Guarantied  Parties,  including fees and  disbursements of counsel
(including the allocated cost of inhouse counsel and staff),  in connection with
the enforcement of this Guaranty (whether or not suit is brought).

         15. No modification of this Guaranty shall be effective for any purpose
unless  it is in  writing  and  executed  by an  officer  of the  Agent  and the
Guarantor   authorized  to  do  so.  This  Guaranty  merges  all   negotiations,
stipulations  and  provisions  relating to the subject  matter of this  Guaranty
which preceded or may accompany the execution of this Guaranty.

         16.  This  Guaranty  and the  rights  and  obligations  of the  parties
hereunder  shall be construed in accordance  with and be governed by the laws of
the State of New York without  reference to the  principles of conflicts of laws
thereof.

         17. This Guaranty may be executed in any number of counterparts  and by
the different  parties  hereto on separate  counterparts,  each of which when so
executed and  delivered  shall be an original,  but all of which shall  together
constitute one and the same instrument.

         18. Any  indebtedness  of the  Borrower  now or  hereafter  held by the
Guarantor  is hereby  subordinated  to the  indebtedness  of the Borrower to the
Agent and the Guarantied  Parties;  and such indebtedness of the Borrower to the
Guarantor if the Agent so requests shall be collected,  enforced and received by
the  Guarantor as trustee for the Agent and the  Guarantied  Parties and be paid
over to the Agent on account of the  indebtedness  of the  Borrower to the Agent
and the Guarantied  Parties but without  reducing or affecting in any manner the
liability of the Guarantor under the other provisions of this Guaranty.



                                        7





         19. This Guaranty shall become  effective upon execution  hereof by the
Guarantor.  The Guarantor  shall deliver to the Agent all of the  following,  in
form and  substance  satisfactory  to the Agent and the Banks and in  sufficient
copies for each Bank:

         (a)      Resolutions; Incumbency Certificate.

                           (i)  Copies  of  the  resolutions  of  the  board  of
                  directors  of the  Guarantor  approving  and  authorizing  the
                  execution,  delivery and  performance  of this Guaranty by the
                  Guarantor, certified as of the date hereof by the Secretary or
                  an Assistant Secretary of the Guarantor; and

                           (ii) A  certificate  of the  Secretary  or  Assistant
                  Secretary  of the  Guarantor  certifying  the  names  and true
                  signatures  of the  officers of the  Guarantor  authorized  to
                  execute and deliver this Guaranty.

         (b)  Articles  of  Incorporation;  By-laws  and  Good  Standing  of the
Guarantor. Each of the following documents:

                           (i) the articles or certificate of  incorporation  of
                  the  Guarantor as in effect on the date  hereof,  certified by
                  the  Secretary of State of the State of  incorporation  of the
                  Guarantor  as  of a  recent  date  and  by  the  Secretary  or
                  Assistant Secretary of the Guarantor as of the date hereof and
                  the bylaws of the  Guarantor  as in effect on the date hereof,
                  certified  by the  Secretary  or  Assistant  Secretary  of the
                  Guarantor as of the date hereof; and

                           (ii) a good  standing  certificate  for the Guarantor
                  from the Secretary of State of its state of incorporation  and
                  each state where the  Guarantor is qualified to do business as
                  a foreign corporation as of a recent date.

         20. Unless otherwise specified herein or therein,  all terms defined in
this  Guaranty  shall have  meanings  assigned to them in the  Revolving  Credit
Agreement.

         21. All notices and other communications  hereunder shall be delivered,
in the manner and with the effect  provided in the  Revolving  Credit  Agreement
and, in the case of the Guarantor, care of the Borrower.




                                        8





         22. It is not necessary for the Guarantied  Parties to inquire into the
powers of any Guaranteed Party or of the officers, directors or agents acting or
purporting  to act on its  behalf,  and  any  indebtedness  made or  created  in
reliance  upon  the  professed  exercise  of such  powers  shall  be  guaranteed
hereunder.

         Executed as of the      day of         ,      .

                       [Guarantor]

                       By:        --------------------------------------------

                       Title:     --------------------------------------------



TORONTO DOMINION (TEXAS), INC.,
  as Administrative Agent



By: -------------------------------------






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