DATE OF LEASE EXECUTION:  September 21, 1993

                         (To be completed by Landlord)


                                   ARTICLE I

                                REFERENCE DATA


1.1  SUBJECTS REFERRED TO:

     Each reference in this lease to any of the following subjects shall be
construed to incorporate the date stated for that subject in this Section 1.1:

LANDLORD:                               L&E Investment of Massachusetts One,
                                        Inc., a Delaware corporation
 
MANAGING AGENT:                         R.M. Bradley & Co., Inc.
 
LANDLORD'S & MANAGING AGENT'S ADDRESS:  Somerset Court
                                        281 Winter Street
                                        Waltham, Massachusetts  02154
                                        Attention:  Carol MacLeod
 
TENANT:                                 Credit Technologies Inc., a Delaware
                                        corporation
 
TENANT'S ADDRESS (FOR NOTICE AND        281 Winter Street
BILLING):                               Waltham, Massachusetts  02154
                                        Attention:  Accounts Payable
 
 
BUILDING ADDRESS:                       281 Winter Street
                                        Waltham, Massachusetts  02154
 
TENANT'S SPACE:                         Portion of the first floor and second
                                        floor as shown on Exhibit A-1 and
                                        Exhibit A-2 attached hereto, as the
                                        same may be increased from time to
                                        time pursuant to the terms hereof.

                                      -1-

 
RENTABLE FLOOR AREA OF TENANT'S SPACE:  17,580 square feet (12,882 of which
                                        are on the first floor and 4,698 of
                                        which are on the second floor), as
                                        the same may be increased pursuant to
                                        the terms hereof.
 
TENANT'S PROPORTIONATE SHARE:           25.93% (17,580) square feet divided
                                        by 67,800 square feet), as the same
                                        may be increased upon addition to
                                        Tenant's Space.
 
TOTAL RENTABLE FLOOR AREA OF THE
BUILDING:                               67,800 square feet.
 
PARKING SPACES ALLOCATED TO TENANT:     Approximately 70 parking spaces
                                        (calculated at 4.0 unassigned parking
                                        spaces per 1,000 square feet).
 
COMMENCEMENT DATE:                      The earlier to occur of (i) November
                                        1, 1993 or (ii) the substantial
                                        completion of Leasehold Improvements
                                        to be undertaken by Landlord on the
                                        portion of Tenant's Space located on
                                        the second floor of the Building.
 
TERM EXPIRATION DATE:                   The last day of the month in which
                                        the seventh anniversary of the
                                        Commencement Date occurs.
 
APPROXIMATE TERM:                       Seven (7) years.
 
BASE OPERATING COSTS:                   Landlord's Operating Costs for the
                                        year ending December 31, 1994.
 
BASE TAX COSTS:                         Real estate taxes for the Tax Year
                                        1994.
 
ANNUAL RENT:                            $21.50 per rentable square foot/year,
                                        plus $0.75 per rentable square foot
                                        for electricity charges for all of
                                        Tenant's Space except for 2,337
                                        rentable square feet separately
                                        metered and paid for by Tenant.

                                      -2-

 
FIRST FISCAL YEAR FOR TENANT'S PAYING
OPERATING COST ESCALATION:              Year ending December 31, 1995.
 
 
FIRST YEAR FOR TENANT'S PAYING TAX      Tax Year 1995.
ESCALATION:
 
PERMITTED USES:                         General office use.
 
PUBLIC LIABILITY INSURANCE:
 
  BODILY INJURY:
                                        $2,000,000.00 per
                                        person/$2,000,000.00 per accident.
 
  PROPERTY DAMAGE:                      $1,000,000.00

  SPECIAL PROVISIONS:                   Tenant's option to lease additional
                                        space; Tenant's option to expand;
                                        mandatory expansion.
 
FISCAL YEAR:                            January 1, through December 31.
 
TAX YEAR:                               July 1 through June 30 (as the same
                                        may be modified from time to time by
                                        the appropriate municipality or
                                        state); Tax Year 1994 is the Tax Year
                                        beginning July 1, 1993 and all other
                                        Tax Years shall be similarly
                                        determined.
 
1.2  EXHIBITS.

     The exhibits listed below in this Section 1.2 are incorporated in this
Lease by reference and are to be construed as part of this Lease:

     EXHIBIT A-1    Plan showing Tenant's Space on first floor.

     EXHIBIT A-2    Plan showing Tenant's Space on second floor.

     EXHIBIT B      Specifications of Leasehold Improvements.

     EXHIBIT C      Building Standards.

                                      -3-

 
     EXHIBIT D      Landlord's Services.

     EXHIBIT E      Rules and Regulations.

     EXHIBIT F      Mandatory Expansion Space.

 
1.3  TABLE OF CONTENTS.

 
                  
ARTICLE II - PREMISES AND TERM................................................

     Section  2.1   Premises..................................................
     Section  2.2   Term......................................................
     Section  2.3   Extended Terms............................................
     Section  2.4   Mandatory Expansion.......................................
     Section  2.5   Optional Expansion........................................

ARTICLE III - Construction....................................................

    Section   3.1   Acceptance of the Premises................................
    Section   3.2   General Provisions Applicable to Construction.............

    Section   3.3   Representatives...........................................

ARTICLE IV - Rent.............................................................

    Section   4.1   Rent......................................................
    Section   4.2   Operating Costs; Taxes; Escalation........................
    Section   4.3   Estimated Escalation Payments.............................
    Section   4.4   Change of Fiscal Year.....................................
    Section   4.5   Payments..................................................

ARTICLE V - LANDLORD'S COVENANTS..............................................

    Section   5.1   Landlord's Covenants During the Term......................
                    Section  5.1.1  Building Services.........................
                    Section  5.1.2  Additional Building Services..............
                    Section  5.1.3  Repairs...................................
                    Section  5.1.4  Quiet Enjoyment...........................
    Section   5.2   Interruptions.............................................
 

                                      -4-

 
 
                  
ARTICLE VI - TENANT'S COVENANTS...............................................

     Section  6.1   TENANT'S COVENANTS DURING THE TERM........................

                    Section  6.1.1  Tenant's Payments.........................
                    Section  6.1.2  Repairs and Yielding Up...................
                    Section  6.1.3  Occupancy and Use.........................
                    Section  6.1.4  Rules and Regulations.....................
                    Section  6.1.5  Safety Appliances.........................
                    Section  6.1.6  Assignment and Subletting.................
                    Section  6.1.7  Indemnity.................................
                    Section  6.1.8  Tenant's Liability Insurance..............
                    Section  6.1.9  Tenant's Worker's Compensation............
                                    Insurance.................................
                    Section  6.1.10 Landlord's Right of Entry.................
                    Section  6.1.11 Loading...................................
                    Section  6.1.12 Landlord's Costs..........................
                    Section  6.1.13 Tenant's Property.........................
                    Section  6.1.14 Labor or Materialmen's Liens..............
                    Section  6.1.15 Changes or Additions......................
                    Section  6.1.16 Holdover..................................
                    Section  6.1.17 Right of Financial Review.................

ARTICLE VII - CASUALTY AND TAKING.............................................

     Section  7.1   Casualty and Taking.......................................
     Section  7.2   Reservation of Award......................................

ARTICLE VIII - RIGHTS OF MORTGAGEE............................................

     Section  8.1   Priority of Lease.........................................
     Section  8.2   Rights of Mortgage Holders; Limitation of Mortgagee's 
                    Liability.................................................
     Section  8.3   Mortgagee's Election......................................
     Section  8.4   No Prepayment or Modification, Etc........................
     Section  8.5   No Release or Termination.................................
     Section  8.6   Continuing Offer..........................................
     Section  8.7   Mortgagee's Approval......................................

ARTICLE IX - DEFAULT..........................................................

     Section  9.1   Events of Default.........................................
     Section  9.2   Tenant's Obligations After Termination....................
 

                                      -5-

 
 
                   
ARTICLE X - MISCELLANEOUS.....................................................

     Section   10.1  Notice of Lease..........................................
     Section   10.2  Intentionally Omitted....................................
     Section   10.3  Notices From One Party to the Other......................
     Section   10.4  Bind and Inure...........................................
     Section   10.5  No Surrender.............................................
     Section   10.6  No Waiver, Etc...........................................
     Section   10.7  No Accord and Satisfaction...............................
     Section   10.8  Cumulative Remedies......................................
     Section   10.9  Landlord's Right to Cure.................................
     Section   10.10 Estoppel Certificate.....................................
     Section   10.11 Waiver of Subrogation....................................
     Section   10.12 Acts of God..............................................
     Section   10.13 Brokerage................................................
     Section   10.14 Submission Not An Offer..................................
     Section   10.15 Applicable Law And Construction..........................


                                      -6-

 
                                  ARTICLE II

                               PREMISES AND TERM

2.1  PREMISES.

     Subject to and with the benefit of the provisions of this Lease and any
ground lease or land disposition agreement relating to the parcel on which the
Building is located (the "Lot"), Landlord hereby leases to Tenant, and Tenant
leases from Landlord, Tenant's Space in the Building, excluding exterior faces
of exterior walls, the common facilities area and building service fixtures and
equipment serving exclusively or in common other parts of the Building.
Tenant's Space, with such exclusions, is hereinafter referred to as the
"Premises".

     Tenant shall have, as appurtenant to the Premises, the right to use in
common with others entitled thereto: (a) the common facilities included in the
Building or on the Lot, including the parking facility, if any, to the extent
and in the location from time to time designated by Landlord as set forth in
Section 1.1 and (b) the building service fixtures and equipment serving the
Premises.

     Landlord reserves the right from time to time, without unreasonable
interference with Tenant's use, (a) to install, repair, replace, use, maintain
and relocate for service to the Premises and to other parts of the Building or
either, building service fixtures and equipment wherever located in the Building
and (b) to alter or relocate any other common facilities, it being understood
that if any parking facilities are provided, the same may be relocated on or off
the Lot from time to time by Landlord, provided that in all events substitutions
are substantially equivalent.

2.2  TERM.

     To have and to hold for a period (the "Term") commencing on the
Commencement Date and continuing until the Term Expiration Date, unless sooner
terminated as provided in Section 6.1.6, 7.1, or in ARTICLE IX.  Landlord and
Tenant agree to confirm, in writing, the exact Commencement Date upon request of
either party and agree that "substantial completion of Leasehold Improvements to
be undertaken by Landlord on the portion of Tenant's Space located on the second
floor of the Building" shall mean the first to occur of (i) Tenant's occupancy
of said space or (ii) the substantial completion of the Leasehold Improvements
for said space (which may be conclusively determined by a certificate of
completion by a licensed architect or registered engineer).

                                      -7-

 
2.3  EXTENDED TERMS.

     Tenant shall have the right and option to extend the Term for up to two (2)
successive periods of three (3) years each, each such option to be exercisable
by notice given to Landlord not less than nine months prior to the expiration of
the then current term.  If any such option is so exercised, all of the terms,
covenants, conditions and provisions of this Lease shall apply during the Term
as extended except that during each additional three year period, the Annual
Rent shall be the higher of (a) $22.50 per rentable square foot per year or (b)
the fair market rental value of the Premises.  In the event that Tenant
exercises its extension options hereunder, Landlord shall, pursuant to written
notice to Tenant within thirty (30) days following receipt of the applicable
Tenant's extension notice, propose the fair market rental value of the Premises
(the "Landlord's Proposed Fair Market Rent").  The Landlord's Proposed Fair
Market Rent shall constitute the fair market rental value of the Premises for
purposes of this Section 2.3 unless Tenant notifies Landlord within twenty (20)
days of Tenant's receipt of Landlord's Proposed Fair Market Rent proposal that
such Landlord's Proposed Fair Market Rent is not satisfactory to Tenant and
specifies in such notice the name and address of an appraiser designated by
Tenant in accordance with sub-paragraph (b) below (the "Tenant's Appraisal
Notice") in which event the fair market rental value of the Premises shall be
determined by the following procedure:

     (a)  Landlord shall, within ten (10) days after receipt of Tenant's
Appraisal Notice, notify Tenant of the name and address of an appraiser
designated by Landlord.  Such two appraisers shall, within thirty (30) days
after the designation of the second appraiser, make their determinations of the
fair market rental value of the Premises in writing and give notice thereof to
each other and to Landlord and Tenant.  Such two (2) appraisers shall have
fifteen (15) days after the receipt of notice of each other's determinations to
confer with each other and to attempt to reach agreement as to the determination
of the fair market rental value of the Premises.  If such appraisers shall
concur in such determination, they shall give notice thereof to Landlord and
Tenant and such concurrence shall be final and binding upon Landlord and Tenant.
If such appraisers shall fail to concur as to such determination within said
fifteen (15) day period, they shall immediately designate a third appraiser and
shall submit in writing to such third appraiser their respective determinations
of the fair market rental value of the Premises.  If the two appraisers shall
fail to agree upon the designation of such third appraiser within ten (10) days
after said fifteen (15) day period, then they or either of them shall give
notice of such failure to 

                                      -8-

 
agree to Landlord and Tenant and, if Landlord and Tenant fail to agree upon the
selection of such third appraiser within ten (10) days after the appraiser(s)
appointed by the parties give notice as aforesaid, then either party on behalf
of both may apply to the president of the local chapter of the American
Institute of Real Estate Appraisers (provided he or she is not an officer or
employee of an entity actively engaged as an agent working on behalf of Landlord
or Tenant) or on its failure, refusal or inability to act within 10 days of the
application to that person to act, to a court of competent jurisdiction, for the
designation of such third appraiser.

     (b)  All individuals who shall be designated or selected as appraisers
hereunder shall be real estate professionals who shall have had at least ten
(10) years continuous experience in the business of leasing similar space in the
greater Boston area.

     (c)  The third appraiser shall conduct such hearings and investigations as
he or she may deem appropriate and shall, within thirty (30) days after the date
of his or her designation, select either the determination of Landlord's
appraiser or that of Tenant's appraiser, whichever he or she deems more
reasonable given his or her independent determination of the fair market rental
value of the Premises.

     (d)  The determination of the appraisers, as provided above, shall be
conclusive upon the parties and shall have the same force and effect as a
judgment made in a court of competent jurisdiction and either party shall be
entitled to have a judgment entered thereon in any court of competent
jurisdiction.  Landlord shall pay the fees and expenses of the appraiser chosen
by Landlord, Tenant shall pay the fees and expenses of the appraiser chosen by
Tenant, and the fees and expenses of the third appraiser shall be paid in equal
proportions by Landlord and Tenant.

     (e)  If for any reason the fair market rental value shall not have been
determined prior to the commencement of any additional three year period, Tenant
shall pay Annual Rent hereunder at the Annual Rent proposed by Landlord's
appraiser, or the Annual Rent during the next preceding period, whichever is
greater, until the fair market rental value has been determined.  The parties
shall thereafter retroactively adjust such Annual Rent within ten (10) days from
the determination of the fair market rental value of the Premises.

     Unless the context clearly requires otherwise, the word "Term" as used in
this Lease shall mean and include the period set forth in Section 2.2 above and
any period as to which the aforesaid option shall have been exercised.

                                      -9-

 
2.4  MANDATORY EXPANSION.

     On December 1, 1994 (or if not available on such date the date on which
Landlord is able to provide the Mandatory Expansion Space (as hereinafter
defined)) approximately 6,400 square feet of rentable floor area on the second
floor of the Building as shown on Exhibit F attached hereto and incorporated
herein (the "Mandatory Expansion Space") shall be added to the Tenant's Space.
Landlord shall provide a Tenant Allowance of up to $18.00 per rentable square
foot of such space for Leasehold Improvements of the Mandatory Expansion Space
on the terms and conditions of the First Floor Tenant Allowance. In all other
respects, the Mandatory Expansion Space shall be subject to the same terms and
conditions as this lease (including, without limitation, obligations for Annual
Rent and additional rent), provided that the Term for such space shall be
coterminous with this lease.

2.5  OPTIONAL EXPANSION.

     Prior to leasing any space on the first floor of the building not occupied
by Tenant, and not subject to a previous right of first offer, refusal or
expansion, Landlord shall offer such space to Tenant at the same Annual Rent,
additional rent, electrical charges and subject to the same covenants and
obligations of Tenant, provided that the Term thereof shall be coterminous with
this lease.  Tenant shall have the right to accept such offer within five (5)
days after the Landlord's written notice of availability of such space.  If
Tenant does not accept such space prior to the expiration of such five (5) day
period, Landlord shall be free to lease the same to a third party on such terms
and conditions as Landlord shall determine in its sole discretion.

                                  ARTICLE III

                                 CONSTRUCTION

3.1  ACCEPTANCE OF THE PREMISES.

     Tenant hereby agrees to accept the Premises "AS IS" and "AS SHOWN" as of
the Commencement Date, subject only to the provisions of this Lease.  Tenant
further acknowledges that neither Landlord nor any agent of Landlord has made
any representation, express or implied, written, verbal or otherwise as to the
condition of the Premises or the suitability of the Premises for Tenant's
intended use.

                                      -10-

 
     All of Tenant's construction, installation of furnishings and later changes
or additions shall be coordinated with any work being performed by Landlord in
such manner as to maintain harmonious labor relations and not to damage the
Building or Lot or to interfere with Building operations.  Except for
installation of furnishings and the installation of telephone outlets which must
be performed by the local telephone company at Tenant's direction and expense,
the Leasehold Improvements shall be performed by Managing Agent.

     Landlord agrees to use reasonable efforts to complete the work described in
Exhibit B (the "Leasehold Improvements") on or before November 1, 1993.

     Costs incurred by Tenant in connection with the space planning,
architectural design and engineering of the Leasehold Improvements shall be paid
by Landlord.  Landlord shall pay for the Leasehold Improvements; provided,
however, that to the extent that the cost of the Leasehold Improvements
(including without limitation the cost of the data center referenced below)
exceeds the sum of (i) the First Floor Tenant Allowance and (ii) the Second
Floor Tenant Allowance, Tenant shall promptly reimburse Landlord for one hundred
percent (100%) of such excess.  The First Floor Tenant Allowance shall be $15.00
per rentable square foot of Tenant's Space on the first floor of the Building.
The Second Floor Tenant Allowance shall be $18.00 per rentable square foot of
Tenant's Space on the second floor of the Building.  The parties hereby agree
that a reasonable portion of the First Floor Tenant Allowance and/or the Second
Floor Tenant Allowance may be used by Tenant to purchase the data center
currently located within the Premises, subject to the receipt and reasonable
approval by Landlord of satisfactory evidence detailing such purchase.

     Landlord will not approve any construction, alterations, or additions
requiring unusual expense to readapt the Premises to normal office use on lease
termination (including, without limitation, construction of an internal stairway
between the first and second floor of the Premises) or increasing the cost of
construction, insurance or taxes on the Building or of Landlord's Services
called for by Section 5.1 unless Tenant first gives assurances acceptable to
Landlord that such readaptation will be made prior to such termination without
expense to Landlord and makes provisions acceptable to Landlord for payment of
such increased cost.  Landlord will also disapprove any alterations or additions
requested by Tenant which will delay completion of the Premises or the Building.
All changes and additions shall be part of the Building except such items as by
writing at the time of approval the parties agree either shall be removed by
Tenant on 

                                      -11-

 
termination of this Lease, or shall be removed or left at Tenant's election.

3.2  GENERAL PROVISIONS APPLICABLE TO CONSTRUCTION.

     All construction work required or permitted by this Lease, whether by
Landlord or by Tenant, shall be done in a good and workmanlike manner and in
compliance with all applicable laws and all lawful ordinances, regulations and
orders of governmental authority and insurers of the Building. Either party may
inspect the work of the other at reasonable times and promptly shall give notice
of observed defects.

3.3  REPRESENTATIVES.

     Each party authorizes the other to rely in connection with their respective
rights and obligations under this Article III upon approval and other actions on
the party's behalf by a representative to be named by each party upon execution
hereof or by any person designated in substitution or addition by notice to the
party relying.


                                  ARTICLE IV

                                     RENT

4.1  RENT.

     Tenant agrees to pay rent to Landlord, without any offset or reduction
whatever (except as made in accordance with the express provisions of this
Lease), equal to 1/12th of the Annual Rent in equal installments in advance on
the first day of each calendar month included in the Term together with any
additional rent or other charges payable pursuant to this Lease (the sum of
Annual Rent plus any additional rent or other charges is hereinafter referred to
as the "Rent").

          (a)  If the Commencement Date occurs on a day other than the first day
     of a calendar month, Tenant shall pay to Landlord on the first day of the
     succeeding calendar month a pro rata payment of Rent for the partial month
     from the Rent Commencement Date to the first day of the succeeding calendar
     month. Such payment shall constitute payment for the partial month, if any,
     immediately following the Rent Commencement Date.

          (b)  Rent for any partial month shall be paid by Tenant to Landlord at
     such rate on a pro rata basis. Other charges 

                                      -12-

 
     payable by Tenant on a monthly basis, as hereinafter provided, shall
     likewise be prorated.

          (c)  Rent and any other sums due hereunder not paid within five (5)
     days of the date due shall bear interest at the rate of one and one-half
     percent (1 1/2%) per month or fraction thereof (or at any lesser maximum
     legally permissible rate) from the due date until paid.

     Other charges payable by Tenant on a monthly basis, as hereinafter
provided, shall likewise be prorated, and the first payment on account thereof
shall be determined in similar fashion.

4.2  OPERATING COSTS; TAXES; ESCALATION.

     (a)  Commencing with the First Fiscal Year for Tenant's Paying Operating
Costs Escalation, the Annual Rent payable by Tenant shall be adjusted for
increases in operating costs, adjusted to reflect full occupancy for twelve
months ("LandLord's Operating Costs").  The amounts of such adjustments shall be
determined by:

          (i)  Comparing the Base Operating Costs with Landlord's Operating
               Costs for the Fiscal Year; and

         (ii)  Computing Tenant's share on the basis of Tenant's Proportionate
               Share of the difference between Base Operating Costs and
               Landlord's operating Costs, such proportionate share being equal
               to a fraction, the numerator of which is the Rentable Floor Area
               of Tenant's Space, and the denominator of which is the Total
               Floor Area of the Building ("Tenant's Proportionate Share").

     (b)  If Landlord's Operating Costs for any Fiscal Year exceed the Base
Operating Costs or if Landlord's Operating Costs for any partial Fiscal Year
exceed the corresponding fraction of Base Operating Costs, Tenant shall pay, as
additional rent, Tenant's Proportionate Share of such excess (such excess being
referred to hereinafter as "Operating Cost Excess").  Such amount shall be due
and payable after the close of the first Fiscal Year in which an Operating Cost
Excess occurs, on or before the thirtieth (30th) day following receipt by Tenant
of Landlord's Statement (as defined below).  As soon as practicable after the
end of each Fiscal Year ending during the Term and after Lease termination,
Landlord shall render a statement ("Landlord's Statement") in reasonable detail
and according to usual accounting practices certified by Landlord and showing
for the preceding Fiscal Year or fraction thereof, as the case may be,
Landlord's Operating Costs.

                                      -13-

 
     (c)  For purposes of this Article "Landlord's Operating
Costs" shall include:

          (i)  premiums for insurance except premiums for loss of rent if such
               premiums are calculated independently of and not included as part
               of the provisions for other insurance carried by Landlord;

         (ii)  compensation and all fringe benefits, worker's compensation
               insurance premiums and payroll taxes paid by Landlord to, for or
               with respect to all persons engaged in operating, maintaining, or
               cleaning the Building and Lot (or if any of said persons are
               engaged in operating, maintaining or cleaning other buildings or
               lots, a pro rata share thereof as reasonably determined by
               Landlord based upon the percentage of time said persons spend at
               the Building or Lot);

        (iii)  all utility charges not billed directly to tenants by Landlord or
               the utility company, but not including the cost to Landlord of
               electricity furnished for lighting, electrical facilities,
               equipment, machinery, fixtures and appliances used by tenants in
               their respective space (other than Building heating, ventilating,
               and air conditioning equipment) as set forth in Paragraph VII of
               Exhibit D;

         (iv)  payments to independent contractors under service contracts for
               cleaning, operating, managing, maintaining and repairing the
               Building and Lot (which payments may be to affiliates of Landlord
               provided the same are at reasonable and competitive rates
               consistent with the type of occupancy and the services rendered);

          (v)  rent paid by the managing agent or imputed costs equal to the
               loss of rent by Landlord for making available to the managing
               agent space for a Building office on the ground floor or above
               (which space shall not exceed 100 square feet of rentable floor
               area); and

         (vi)  all other reasonable and necessary expenses paid in connection
               with cleaning, operating, managing, maintaining and repairing the
               Building and Lot, or either, and properly chargeable against
               income, it

                                      -14-

 
               being agreed that the cost of all repairs and replacements shall
               be limited to such repair and replacement that is properly
               expensed under the Internal Revenue Code, and it being further
               agreed that if Landlord installs a new or replacement capital
               item for the purpose of reducing Landlord's Operating Costs, the
               cost thereof as reasonably amortized by Landlord, with interest
               at the average prime commercial rate in effect from time to time
               at the then three largest national banks in Boston, Massachusetts
               or the amortized amount, shall be included in Landlord's
               Operating Costs.

     Landlord's Operating Costs shall be computed on an accrual basis and shall
be determined in accordance with generally accepted accounting principles
consistently applied.  Such costs may be incurred directly or by way of
reimbursement, and shall include taxes applicable thereto.  The following shall
be excluded from Landlord's Operating Costs:

          (i)  depreciation;

         (ii)  expenses relating to tenants' alterations;

        (iii)  expenses for which Landlord, by the terms of this Lease or any
               other lease, makes a separate charge;

         (iv)  the cost of any services or systems for that portion of the
               Building occupied by the Landlord or affiliates of Landlord
               (exclusive of space occupied by Landlord or affiliates of
               Landlord in connection with the operation of the Building) and
               which are not provided generally to other tenants in the
               Building;

          (v)  the cost of constructing additional parking spaces, which costs
               shall be treated as a capital cost by Landlord; and

         (vi)  leasing fees or commissions.

     In case of special services which are not rendered to all areas on a
comparable basis, the proportion allocable to the Premises shall be the same
proportion which the Rentable Floor Area of Tenant's Space bears to the total
rentable floor area to which such service is so rendered (such latter area to be
determined in the same manner as the Total Rentable Floor Area of the Building).

                                      -15-

 
     (d)  Commencing with the First Year for Tenant's Paying Tax Escalation, the
Annual Rent payable by Tenant shall be adjusted for increases in real estate
taxes, adjusted to reflect full occupancy for twelve months ("Landlord's Tax
Costs").  The amounts of such adjustments shall be determined by:

          (i)  Comparing the Base Tax Costs with Landlord's Tax Costs for the
               Tax Year; and

         (ii)  Computing Tenant's share on the basis of Tenant's Proportionate
               Share of the difference between Base Tax Costs and Landlord's Tax
               Costs.

     (e)  If Landlord's Tax Costs for any Tax Year exceed the Base Tax Costs or
if Landlord's Tax Costs for any partial Tax Year exceed the corresponding
fraction of Base Tax Costs, Tenant shall pay, as additional rent, Tenant's
Proportionate Share of such excess (such excess being referred to hereinafter as
"Tax Excess").  Such amount shall be due and payable after the close of the
first Tax Year in which a Tax Excess occurs, on or before the thirtieth (30th)
day following receipt by Tenant of Landlord's Tax Statement (as defined below).
As soon as practicable after the end of each Tax Year ending during the Term and
after Lease termination, Landlord shall render a statement ("Landlord's Tax
Statement") in reasonable detail and according to usual accounting practices
certified by Landlord and showing for the preceding Tax Year or fraction
thereof, as the case may be, Landlord's Tax Costs.

     (e)  For purposes of this Article "Landlord's Tax Costs" shall include:

          (i)  real estate taxes on the Building and Lot, installments and
               interest on assessments for public betterments or public
               improvements; and

         (ii)  reasonable expenses of any proceedings for abatement of taxes and
               assessments with respect to any Tax Year or fraction of a Tax
               Year;

     The term "real estate taxes" as used above shall mean all taxes of every
kind and nature assessed by any governmental authority on the Lot, the Building
and improvements, or both, which Landlord shall become obligated to pay because
of or in connection with the ownership, leasing and operation of the Lot, the
Building and improvements, or both, subject to the following: There shall be
excluded from such taxes all income taxes, excess profits taxes, excise taxes,
franchise taxes, and estate, succession, inheritance and transfer taxes,
provided, however, 

                                      -16-

 
that if at any time during the Term the present system of ad valorem taxation of
real property shall be changed so that in lieu of the whole or any part of the
ad valorem tax on real property, there shall be assessed on Landlord a capital
levy or other tax on the gross rents received with respect to the Lot, Building
and improvements, or both, or a federal, state, county, municipal, or other
local income, franchise, excise or similar tax, assessment, levy or charge
(distinct from any now in effect) measured by or based, in whole or in part,
upon any such gross rents, then any and all of such taxes, assessments, levies
or charges, to the extent so measured or based, shall be deemed to be included
within the term "real estate taxes." If Landlord shall receive any tax refund or
reimbursement of taxes or sum in lieu thereof with respect to any Tax Year then
out of any balance remaining thereof after deducting Landlord's expenses
reasonably incurred in obtaining such refund, Landlord shall credit against
Tenant's next payment of Tax Excess, provided there does not then exist a
default of Tenant, an amount equal to Tenant's Proportionate Share of such
refund or reimbursement provided, that in no event shall Tenant be entitled to a
credit in excess of the amount of any payments made by Tenant on account of real
estate tax increases for such Tax Year pursuant to this Section 4.2.

     Notwithstanding any other provision of Section 4.2 hereof, if the Term
expires or is terminated as of a date other than the last day of a Fiscal Year
or Tax Year as applicable, then for such fraction of a Fiscal Year or Tax Year
at the end of the Term, Tenant's last payment to Landlord under Section 4.2
shall be made on the basis of Landlord's best estimate of the items otherwise
includable in Landlord's Statement or Landlord's Tax Statement and shall be made
on or before the later of (a) ten (10) days after Landlord delivers such
estimate to Tenant or (b) the last day of the Term, with an appropriate payment
or refund upon submission of Landlord's Statement or Landlord's Tax Statement as
applicable which statement shall represent Landlord's actual costs. Tenant shall
have the right, upon reasonable prior written notice to Landlord, to examine
Landlord's books and records with respect to the items in the aforementioned
Landlord's Statement or Landlord's Tax Statement during normal business hours,
provided that Landlord receive such notice within thirty (30) days following the
delivery to Tenant of Landlord's Statement.

4.3  ESTIMATED ESCALATION PAYMENTS.

     If, with respect to any fiscal year or tax year (as appropriate) or
fraction thereof during the Term, Landlord estimates that Tenant shall be
obligated to pay Operating Cost Escalation or Tax Escalation.  Then Tenant shall
pay, as additional rent, on the first day of each month of such fiscal year or
tax year (as appropriate) and each ensuing fiscal 

                                      -17-

 
year thereafter, Estimated Monthly Escalation Payments equal to 1/12th of the
estimated Operating Cost Escalation for the respective fiscal year plus 1/12 of
the estimated Tax Escalation for the respective Tax Year, with an appropriate
additional payment or refund to be made within thirty (30) days after Landlord's
Statement or Landlord's Tax Statement as applicable is delivered to Tenant.
Landlord may adjust such Estimated Monthly Escalation Payment from time to time
and at any time during a fiscal year, and Tenant shall pay, as additional rent,
on the first day of each month following receipt of Landlord's notice thereof,
the adjusted Estimated Monthly Escalation Payment.

4.4  CHANGE OF FISCAL YEAR.

     Landlord shall have the right from time to time to change the periods of
accounting under Section 4.2 to any annual period other than a fiscal year, and
upon any such change all items referred to in this Section 4.4 shall be
appropriately apportioned.  In all Landlord's Statements rendered under this
Section 4.4, amounts for periods partially within and partially without the
accounting periods shall be appropriately apportioned, and any items which are
not determinable at the time of a Landlord's Statement shall be included therein
on the basis of Landlord's estimate, and with respect thereto Landlord shall
render promptly after determination a supplemental Landlord's Statement, and
appropriate adjustment shall be made according thereto.  All Landlord's
Statements shall be prepared on an accrual basis of accounting.

4.5  PAYMENTS.

     All payments of Annual Rent and additional rent shall be made to Managing
Agent, or to such other person as Landlord may from time to time designate.  If
any installment of Annual Rent or additional rent or on account of leasehold
improvements is paid more than five (5) days after the due date thereof, it
shall, at Landlord's election, bear interest at a rate equal to the average
prime commercial rate from time to time established by the three largest
national banks in Boston, Massachusetts plus 4% per annum from such due date,
which interest shall be immediately due and payable as further additional rent.

                                      -18-

 
                                   ARTICLE V

                             LANDLORD'S COVENANTS

5.1  LANDLORD'S COVENANTS DURING THE TERM.

     Landlord covenants during the Term:

     5.1.1   Building Services - To furnish, through Landlord's employees or
independent contractors, the services listed in Exhibit D;

     5.1.2   Additional Building Services - To furnish, through Landlord's
employees or independent contractors, reasonable additional Building operation
services upon reasonable advance request of Tenant at equitable rates from time
to time established by Landlord to be paid by Tenant;

     5.1.3   Repairs - Except as otherwise provided in ARTICLE VII of this
Lease, to make such repairs to the roof, exterior walls, floor slabs, other
structural components and common facilities of the Building as may be necessary
to keep them in serviceable condition; and

     5.1.4   Quiet Enjoyment - That Landlord has the right to make this Lease
and that Tenant on paying the rent and performing its obligations hereunder
shall peacefully and quietly have, hold and enjoy the Premises throughout the
Term without any manner of hindrance or molestation from Landlord or anyone
claiming under Landlord, subject however to all the terms and provisions hereof.

5.2  INTERRUPTIONS.

     Landlord shall not be liable to Tenant for any compensation or reduction of
rent by reason of inconvenience or annoyance or for loss of business arising
from power losses or shortages or from the necessity of Landlord's entering the
Premises for any of the purposes authorized in this Lease or for repairing the
Premises or any portion of the Building or Lot.  In case Landlord is prevented
or delayed from making any repairs, alterations or improvements, or furnishing
any service or performing any other covenant or duty to be performed on
Landlord's part, by reason of any cause beyond Landlord's reasonable control,
Landlord shall not be liable to Tenant therefor, nor, except as expressly
otherwise provided in ARTICLE VII, shall Tenant be entitled to any abatement or
reduction of rent by reason thereof, nor shall the same give rise to a claim in
Tenant's favor that such failure constitutes actual or constructive, total or
partial, eviction from the Premises.

                                      -19-

 
     Landlord reserves the right to stop any service or utility system when
necessary by reason of accident or emergency or until necessary repairs have
been completed.  Except in case of emergency repairs, Landlord will give Tenant
reasonable advance notice of any contemplated stoppage and will use reasonable
efforts to avoid unnecessary inconvenience to Tenant by reason thereof.

     Landlord also reserves the right to institute such policies, programs and
measures as may be necessary, required or expedient for the conservation or
preservation of energy or energy services or as may be necessary or required to
comply with applicable codes, rules, regulations or standards.


                                  ARTICLE VI

                              TENANT'S COVENANTS

6.1  TENANT'S COVENANTS DURING THE TERM.

     Tenant covenants during the Term and such further time as
Tenant occupies any part of the Premises:

     6.1.1   Tenant's Payments - To pay when due (a) all Annual Rent and
additional rent, (b) all taxes which may be imposed on Tenant's personal
property in the Premises (including, without limitation, Tenant's fixtures and
equipment) regardless to whomever assessed, (c) all charges by public utilities
for telephone and other utility services (including service inspections
therefor) rendered to the Premises not otherwise required hereunder to be
furnished by Landlord without charge and not consumed in connection with any
services required to be furnished by Landlord without charge and (d) as
additional rent, all charges of Landlord for services rendered pursuant to
Section 5.1.2 hereof;

     6.1.2   Repairs and Yielding Up - Except as otherwise provided in ARTICLE
VII and Section 5.1.3, to keep the Premises in good order, repair and condition,
reasonable wear only excepted; and at the expiration or termination of this
Lease peaceably to yield up the Premises and all changes and additions therein
in such order, repair and condition, first removing all goods and effects of
Tenant and any items, the removal of which is required by agreement or specified
herein to be removed at Tenant's election and which Tenant elects to remove, and
repairing all damage caused by such removal and restoring the Premises and
leaving them clean and neat;

                                      -20-

 
     6.1.3   Occupancy and Use - To use and occupy the Premises only for the
Permitted Uses; not to injure or deface the Premises, Building, or Lot; and not
to permit in the Premises any use thereof which is improper, offensive, contrary
to law or ordinance, or liable to create a nuisance or to invalidate or increase
the premiums for any insurance on the Building or its contents or liable to
render necessary any alteration or addition to the Building;

     6.1.4   Rules and Regulations - To comply with the Rules and Regulations
set forth in Exhibit E and all other reasonable Rules and Regulations hereafter
made by Landlord, of which Tenant has been given notice, for the care and use of
the Building and Lot and their facilities and approaches, it being understood
that Landlord shall not be liable to Tenant for the failure of other tenants of
the Building to conform to such Rules and Regulations;

     6.1.5   Safety Appliances - To keep the Premises equipped with all safety
appliances required by law or ordinance or any other regulation of any public
authority because of any use made by Tenant and to procure all licenses and
permits so required because of such use and, if requested by Landlord, to do any
work so required because of such use, it being understood that the foregoing
provisions shall not be construed to broaden in any way Tenant's Permitted Uses;

     6.1.6   Assignment and Subletting - Not without the prior written consent
of Landlord to assign this Lease, to make any sublease, or to permit occupancy
of the Premises or any part thereof by anyone other than Tenant, voluntarily or
by operation of law (it being understood that in no event shall Landlord consent
to any such assignment, sublease or occupancy if the same is on terms more
favorable to the successor occupant than to the then occupant); as additional
rent, to reimburse Landlord promptly for reasonable legal and other expenses
incurred by Landlord in connection with any request by Tenant for consent to
assignment or subletting; no assignment or subletting shall affect the
continuing primary liability of Tenant (which, following assignment, shall be
joint and several with the assignee); no consent to any of the foregoing in a
specific instance shall operate as a waiver in any subsequent instance.
Landlord's consent to assignment or subletting by Tenant shall not be
unreasonably withheld, provided that such assignee or subtenant pays therefor
the greater of the Annual Rent and additional rent then payable hereunder, or
the then fair market rent for the Premises as reasonably determined by Landlord;
and provided further that Landlord shall not be deemed unreasonable for
withholding its consent to any assignment or subletting the arrangements for
which are to be made through any broker other than Landlord or its affiliates.
In the event that 

                                      -21-

 
any assignee or subtenant pays to Tenant any amounts in excess of the Annual
Rent and additional rent then payable hereunder, or pro rata portion thereof on
a square footage basis for any portion of the Premises, Tenant shall promptly
pay said excess to Landlord as and when received by Tenant. If Tenant requests
Landlord's consent to assign this Lease or sublet more than twenty-five percent
(25%) of the Premises, Landlord shall have the option, exercisable by written
notice to Tenant given within ten (10) days after receipt of such request, to
terminate this Lease as of a date specified in such notice which shall not be
less than thirty (30) or more than sixty (60) days after the date of such
notice;

     6.1.7   Indemnity - To defend, with counsel reasonably acceptable to
Landlord, save harmless and indemnify Landlord from any liability for injury,
loss, accident or damage to any person or property and from any claims, actions,
proceedings and expenses and costs in connection therewith (including, without
implied limitation, reasonable counsel fees): (i) arising from the omission,
fault, willful act, negligence or other misconduct of Tenant or from any use
made or thing done or occurring on the Premises not due to the gross negligence
of Landlord or (ii) resulting from the failure of Tenant to perform and
discharge its covenants and obligations under this Lease;

     6.1.8   Tenant's Liability Insurance - To maintain public liability
insurance on the Premises in amounts which shall, at the beginning of the Term,
be at least equal to the limits set forth in Section 1.1 of this Lease, and from
time to time during the Term, shall be for such higher limits, if any, as are
customarily carried in the area in which the Premises are located on property
similar to the Premises and used for similar purposes and to furnish Landlord
with certificates thereof;

     6.1.9   Tenant's Worker's Compensation Insurance - To keep all of Tenant's
employees working in the Premises covered by worker's compensation insurance in
statutory amounts and to furnish Landlord with certificates thereof;

     6.1.10  Landlord's Right of Entry - To permit Landlord and Landlord's
agents entry: to examine the Premises at reasonable times and, if Landlord shall
so elect, to make repairs or replacements; to remove, at Tenant's expense, any
changes, additions, signs, curtains, blinds, shades, awnings, aerials, flagpoles
or the like to which Landlord has not consented in writing; and to show the
Premises to prospective tenants during the twelve (12) months preceding
expiration of the Term and to prospective purchasers and mortgagees at all
reasonable times;

                                      -22-

 
     6.1.11  Loading - Not to place a load upon the Premises exceeding an
average rate of fifty (50) pounds of live load per square foot or floor area,
and not to move any safe, vault or other heavy equipment in, about or out of the
Premises except in such manner and at such times as Landlord shall in each
instance approve; Tenant's business machines and mechanical equipment which
cause vibration or noise that may be transmitted to the Building structure or to
any other leased space in the Building shall be placed and maintained by Tenant
in settings of cork, rubber, spring or other types of vibration eliminators
sufficient to eliminate such vibration or noise;

     6.1.12  Landlord's Costs - In case Landlord shall be made party to any
litigation commenced by or against Tenant or by or against any parties in
possession of the Premises or any part thereof claiming under Tenant, to pay, as
additional rent, all costs including, without implied limitation, reasonable
counsel fees incurred by or imposed upon Landlord in connection with such
litigation and, as additional rent, also to pay all such costs and fees incurred
by Landlord in connection with the successful enforcement by Landlord of any
obligations of Tenant under this Lease;

     6.1.13  Tenant's Property - All the furnishings, fixtures, equipment,
effects and property of every kind, nature and description of Tenant and of all
persons claiming by, through or under Tenant which, during the continuance of
this Lease or any occupancy of the Premises by Tenant or anyone claiming under
Tenant, may be on the Premises or elsewhere in the Building or on the Lot shall
be at the sole risk and hazard of Tenant and, if the whole or any part thereof
shall be destroyed or damaged by fire, water or otherwise, or by the leakage or
bursting of water pipes, steam pipes or other pipes, by theft, or from any other
cause, no part of said loss or damage is to be charged to or to be borne by
Landlord unless due to the gross negligence of Landlord;

     6.1.14  Labor or Materialmen's Liens - To pay promptly when due the entire
cost of any work done on the Premises by Tenant, its agents, employees or
independent contractors; not to cause or permit any liens for labor or materials
performed or furnished in connection therewith to attach to the Premises; and
immediately to discharge any such liens which may so attach;

     6.1.15  Changes or Additions - Not to make any changes or additions to
the Premises without Landlord's prior written consent, provided that Tenant
shall reimburse Landlord, as additional rent, for all costs incurred by Landlord
in reviewing Tenant's proposed changes or additions, and provided further that,
in order 

                                      -23-

 
to protect the functional integrity of the Building, all such changes
and additions shall be performed by Managing Agent; and

     6.1.16  Holdover - To pay to Landlord one and one-half times the then fair
market rent as conclusively determined by Landlord or twice the total of the
Annual Rent and additional rent then applicable for each month or portion
thereof Tenant shall retain possession of the Premises or any part thereof after
the termination of this Lease, whether by lapse of time or otherwise, and also
to pay all damages sustained by Landlord on account thereof; the provisions of
this subsection shall not operate as a waiver by Landlord of the right of re-
entry provided in this Lease; at the option of Landlord exercised by a written
notice given to Tenant while such holding over continues, such holding over
shall constitute an extension of this Lease for a period of one year.

     6.1.17  Right of Financial Review - To allow Landlord and any holder of a
mortgage on the Premises to examine Tenant's books, including, without
limitation, its financial statements, operating statements and balance sheets
upon reasonable advance notice from Landlord to Tenant.  Such review shall be
conducted no more frequently than once in any six (6) month period.


                                  ARTICLE VII

                              CASUALTY AND TAKING

7.1  CASUALTY AND TAKING.

     In case during the Term all or any substantial part of the Premises,
Building or Lot, or any one or more of them, are damaged materially by fire or
any other cause or by action of public or other authority in consequence thereof
or are taken by eminent domain or Landlord receives compensable damage by reason
of anything lawfully done in pursuance of public or other authority, this Lease
shall terminate at Landlord's election, which may be made, notwithstanding
Landlord's entire interest may have been divested, by notice to Tenant within
thirty (30) days after the occurrence of the event giving rise to the election
to terminate, which notice shall specify the effective date of termination which
shall be not less than thirty (30) nor more than sixty (60) days after the date
of notice of such termination.  If in any such case the Premises are rendered
unfit for use and occupation and the Lease is not so terminated, Landlord shall
use due diligence to put the Premises, or, in case of a taking, what may remain
thereof (excluding any items installed or paid for by Tenant which Tenant may be
required or permitted to remove) into proper condition for use and occupation to
the extent permitted by the net award of 

                                      -24-

 
insurance or damages available to Landlord, and a just proportion of the Annual
Rent and additional rent according to the nature and extent of the injury shall
be abated until the Premises or such remainder shall have been put by Landlord
in such condition; and in case of a taking which permanently reduces the area of
the Premises, a just proportion of the Annual Rent and additional rent shall be
abated for the remainder of the Term and an appropriate adjustment shall be made
to the Annual Estimated Operating Expenses.

7.2  RESERVATION OF AWARD.

     Landlord reserves to itself any and all rights to receive awards made for
damages to the Premises, Building or Lot and the leasehold hereby created, or
any one or more of them, accruing by reason of exercise of eminent domain or by
reason of anything lawfully done in pursuance of public or other authority.
Tenant hereby releases and assigns to Landlord all Tenant's rights to such
awards and covenants to deliver such further assignments and assurances thereof
as Landlord may from time to time request and hereby irrevocably designates and
appoints Landlord as its attorney-in-fact to execute and deliver to Tenant's
name and behalf all such further assignments thereof. It is agreed and
understood, however, that Landlord does not reserve to itself, and Tenant does
not assign to Landlord, any damages payable for (i) movable trade fixtures
installed by Tenant, or anybody claiming under Tenant, at its own expense or
(ii) relocation expenses recoverable by Tenant from such authority in a separate
action.


                                 ARTICLE VIII

                              RIGHTS OF MORTGAGEE

8.1  PRIORITY OF LEASE.

     This Lease is and shall continue to be subject and subordinate to any
presently existing mortgage or deed of trust of record covering the Lot or
Building or both (the "mortgaged premises"). The holder of such presently
existing mortgage or deed of trust shall have the election to subordinate the
same to the rights and interests of Tenant under this Lease exercisable by
filing with the appropriate recording office a notice of such election,
whereupon the Tenant's rights and interests hereunder shall have priority over
such mortgage or deed of trust.

     Unless the option provided for in the next following sentence shall be
exercised, this Lease shall be superior to and shall not be subordinate to, any
mortgage, deed of trust or other voluntary 

                                      -25-

 
lien hereafter placed on the mortgaged premises. The holder of any such
mortgage, deed of trust or other voluntary lien shall have the option to
subordinate this Lease to the same, provided that such holder enters into an
agreement with Tenant by the terms of which the holder will agree to recognize
the rights of Tenant under this Lease and to accept Tenant as tenant of the
Premises under the terms and conditions of this Lease in the event of
acquisition of title by such holder through foreclosure proceedings or otherwise
and Tenant will agree to recognize the holder of such mortgage as Landlord in
such event, which agreement shall be made to expressly bind and inure to the
benefit of the successors and assigns of Tenant and of the holder and upon
anyone purchasing the mortgaged premises at any foreclosure sale. Any such
mortgage to which this Lease shall be subordinated may contain such terms,
provisions and conditions as the holder deems usual or customary.

8.2  RIGHTS OF MORTGAGE HOLDERS; LIMITATION OF MORTGAGEE'S LIABILITY.

     The word "mortgage" as used herein includes mortgages, deeds of trust or
other similar instruments evidencing other voluntary liens or encumbrances and
modifications, consolidations, extensions, renewals, replacements and
substitutes thereof. The word "holder" shall mean a mortgagee and any subsequent
holder or holders of a mortgage. Until the holder of a mortgage shall enter and
take possession of the Premises for the purpose of foreclosure, such holder
shall have only such rights of Landlord as are necessary to preserve the
integrity of this Lease as security. Upon entry and taking possession of the
Premises for the purpose of foreclosure, such holder shall have all the rights
of Landlord. Notwithstanding any other provision of this Lease to the contrary,
including without limitation Section 10.4, no such holder of a mortgage shall be
liable, either as mortgagee or as assignee, to perform, or be liable in damages
for failure to perform, any of the obligations of Landlord unless and until such
holder shall enter and take possession of the Premises for the purpose of
foreclosure, and such holder shall not in any event be liable to perform or
liable in damages for failure to perform the obligations of Landlord under
Section 3.1. Upon entry for the purpose of foreclosure, such holder shall be
liable to perform all of the obligations of Landlord (except for the obligations
under Section 3.1), subject to and with the benefit of the provisions of Section
10.4, provided that a discontinuance of any foreclosure proceeding shall be
deemed a conveyance under said provisions to the owner of the equity of the
Premises.

                                      -26-

 
8.3  MORTGAGEE'S ELECTION.

     Notwithstanding any other provision to the contrary contained in this
Lease, if prior to substantial completion of Landlord's obligations under
Article III, any holder of a first mortgage on the mortgaged premises enters and
takes possession thereof for the purpose of foreclosing the mortgage, such
holder may elect, by written notice given to Tenant and Landlord at any time
within ninety (90) days after such entry and taking of possession, not to
perform Landlord's obligations under Article III, and in such event such holder
and all persons claiming under it shall be relieved of all obligations to
perform, and all liability for failure to perform, said Landlord's obligations
under Article III, and Tenant may terminate this Lease and all its obligations
hereunder by written notice to Landlord and such holder given within thirty (30)
days after the day on which such holder shall have given its notice as
aforesaid.

8.4  NO PREPAYMENT OR MODIFICATION, ETC.

     Tenant shall not pay Annual Rent, additional rent or any other charge more
than ten (10) days prior to the due dates thereof. No prepayment of Annual Rent,
additional rent or other charge, no assignment of this Lease and no agreement to
modify so as to reduce the rent, change the Term or otherwise materially change
the rights of Landlord under this Lease, or to relieve Tenant of any obligations
or liability under this Lease, shall be valid unless consented to in writing by
Landlord's mortgagees of record, if any.

8.5  NO RELEASE OR TERMINATION.

     No act or failure to act on the part of Landlord which would entitle Tenant
under the terms of this Lease, or by law, to be relieved of Tenant's obligations
hereunder or to terminate this Lease, shall result in a release or termination
of such obligations or a termination of this Lease unless (i) Tenant shall have
first given written notice of Landlord's act or failure to act to Landlord's
mortgagees of record, if any, specifying the act or failure to act on the part
of Landlord which could or would give basis to Tenant's rights and (ii) such
mortgagees, after receipt of such notice, have failed or refused to correct or
cure the condition complained of within a reasonable time thereafter, but
nothing contained in this Section 8.5 shall be deemed to impose any obligation
on any such mortgagee to correct or cure any such condition. "Reasonable time"
as used above means and includes a reasonable time to obtain possession of the
mortgaged premises, if the mortgagee elects to do so, and a reasonable time to
correct or cure the condition if such condition is determined to exist.

                                      -27-

 
8.6  CONTINUING OFFER.

     The covenants and agreements contained in this Lease with respect to the
rights, powers and benefits of a mortgagee (particularly, without limitation
thereby, the covenants and agreements contained in this Article VIII) constitute
a continuing offer to any person, corporation or other entity, which by
accepting or requiring an assignment of this Lease or by entry or foreclosure
assumes the obligations herein set forth with respect to such mortgagee; such
mortgagee is hereby constituted a party to this Lease as an obligee hereunder to
the same extent as though its name were written herein as such; and such
mortgagee shall be entitled to enforce such provisions in its own name. Tenant
agrees on request of Landlord to execute and deliver from time to time any
agreement which may reasonably be deemed necessary to implement the provisions
of this Article VIII.

8.7  MORTGAGEE'S APPROVAL.

     Landlord's obligation to perform its covenants and agreements hereunder is
subject to the condition precedent that this Lease be approved by the holder of
any mortgage of which the Premises are a part and by the issuer of any
commitment to make a mortgage loan which is in effect on the date hereof.
Unless Landlord gives Tenant written notice within thirty (30) business days
after the date hereof that such holder or issuer, or both, disapprove this
Lease, then this condition shall be deemed to have been satisfied or waived and
the provisions of this Section 8.6 shall be of no further force or effect.


                                  ARTICLE IX

                                    DEFAULT

9.1  EVENTS OF DEFAULT.

     If any default by Tenant continues after notice, in case of Annual Rent,
additional rent, or any other monetary obligation to Landlord for more than ten
(10) days or, in any other case, for more than thirty (30) days and such
additional time, if any, as is reasonably necessary to cure the default if the
default is of such a nature that it cannot reasonably be cured in thirty (30)
days and Tenant diligently endeavors to cure such default; or if Tenant becomes
insolvent, fails to pay its debts as they fall due, files a petition under any
chapter of the U.S. Bankruptcy Code, 11 U.S.C. 101 et seq., as it may be amended
(or any similar petition 

                                      -28-

 
under any insolvency law of any jurisdiction), or if such petition is filed
against Tenant; or if Tenant proposes any dissolution, liquidation, composition,
financial reorganization or recapitalization with creditors, makes an assignment
or trust mortgage for the benefit of creditors, or if a receiver, trustee,
custodian or similar agent is appointed or takes possession with respect to any
property of Tenant; or if the leasehold hereby created is taken on execution or
other process of law in any action against Tenant; then, and in any such case,
Landlord and the agents and servants of Landlord may, in addition to and not in
derogation of any remedies for any preceding breach of covenant, immediately or
at any time thereafter while such default continues and without further notice,
at Landlord's election, do any one or more of the following: (1) give Tenant
written notice stating that the Lease is terminated, effective upon the giving
of such notice or upon a date stated in such notice, as Landlord may elect, in
which event the Lease shall be irrevocably extinguished and terminated as stated
in such notice without any further action, or (2) with or without process of
law, in a lawful manner, enter and repossess the Premises as of Landlord's
former estate, and expel Tenant and those claiming through or under Tenant, and
remove its and their effects, without being guilty of trespass, in which event
the Lease shall be irrevocably extinguished and terminated at the time of such
entry, or (3) pursue any other rights or remedies permitted by law. Any such
termination of the Lease shall be without prejudice to any remedies which might
otherwise be used for arrears of rent or prior breach of covenant, and in the
event of such termination Tenant shall remain liable under this Lease as
hereinafter provided. Tenant hereby waives all statutory rights (including,
without limitation, rights of redemption, if any) to the extent such rights may
be lawfully waived, and Landlord, without notice to Tenant, may store Tenant's
effects and those of any person claiming through or under Tenant at the expense
and risk of Tenant and, if Landlord so elects, may sell such effects at public
auction or private sale and apply the net proceeds to the payment of all sums
due to Landlord from Tenant, if any, and pay over the balance, if any, to
Tenant.

9.2  TENANT'S OBLIGATIONS AFTER TERMINATION.

     In the event that this Lease is terminated under any of the provisions
contained in Section 9.1 or shall be otherwise termi nated for breach of any
obligation of Tenant, Tenant covenants to pay forthwith to Landlord, as
compensation, (a) a sum equal to the tenant allowances paid by Landlord as set
forth in Article II and Article III and (b) the excess of the total rent
reserved for the residue of the Term over the rental value of the Premises for
said residue of the Term.  In calculating the rent reserved, there shall be
included, in addition to the Annual Rent and all additional rent, the value of
all other consideration agreed to be 

                                      -29-

 
paid or performed by Tenant for said residue. Tenant further covenants as an
additional and cumulative obligation after any such ending to pay punctually to
Landlord all the sums and perform all the obligations which Tenant covenants in
this Lease to pay and to perform in the same manner and to the same extent and
at the same time as if this Lease had not been terminated. In calculating the
amounts to be paid by Tenant under the next foregoing covenant, Tenant shall be
credited with any amount paid to Landlord as compensation as provided in the
first sentence of this Section 9.2 and also with the net proceeds of any rents
obtained by Landlord by reletting the Premises, after deducting all Landlord's
expenses in connection wit such reletting, including, without implied
limitation, all repossession costs, brokerage commissions, fees for legal
services and expenses of preparing the Premises for such reletting, it being
agreed by Tenant that Landlord may (i) relet the Premises or any part or parts
thereof for a term or terms which may at Landlord's option be equal to or less
than or exceed the period which would otherwise have constituted the balance of
the Term and may grant such concessions and free rent as Landlord in its sole
judgment considers advisable or necessary to relet the same and (ii) make such
alterations, repairs and decorations in the Premises as Landlord in its sole
judgment considers advisable or necessary to relet the same, and no action of
Landlord in accordance with the foregoing or failure to relet or to collect rent
under reletting shall operate or be construed to release or reduce Tenant's
liability as aforesaid.

     So long as at least twelve (12) months of the Term remain unexpired at the
time of such termination, in lieu of any other damages or indemnity and in lieu
of full recovery by Landlord of all sums payable under all the foregoing
provisions of this Section 9.2, Landlord may by written notice to Tenant, at any
time after this Lease is terminated under any of the provisions contained in
Section 9.l, or is otherwise terminated for breach of any obligation of Tenant
and before such full recovery, elect to recover, and Tenant shall thereupon pay,
as liquidated damages, an amount equal to the aggregate of the Annual Rent and
additional rent accrued under Article IV in the twelve (12) months ended next
prior to such termination plus the amount of Annual Rent and additional rent of
any kind accrued and unpaid at the time of termination and less the amount of
any recovery by Landlord under the foregoing provisions of this Section 9.2 up
to the time of payment of such liquidated damages.

     Nothing contained in this Lease shall, however, limit or prejudice the
right of Landlord to prove and obtain in proceedings for bankruptcy or
insolvency by reason of the termination of this Lease, an amount equal to the
maximum allowed by any statute or 

                                      -30-

 
rule of law in effect at the time when, and governing the proceedings in which, 
the damages are to be proved, whether or not the amount be greater, equal to, or
less than the amount of the loss or damages referred to above.


                                   ARTICLE X

                                 MISCELLANEOUS

10.1 NOTICE OF LEASE.

     Upon request of either party, both parties shall execute and deliver, after
the Term begins, a short form of this Lease in form appropriate for recording or
registration, and if this Lease is terminated before the Term expires, an
instrument in such form acknowledging the date of termination.

10.2 INTENTIONALLY OMITTED.

10.3 NOTICES FROM ONE PARTY TO THE OTHER.

     All notices required or permitted hereunder shall be in writing and
addressed, if to the Tenant, at Tenant's Address or such other address as Tenant
shall have last designated by notice in writing to Landlord and, if to Landlord,
at Landlord's Address or such other address as Landlord shall have last
designated by notice in writing to Tenant.  Any notice shall be deemed duly
given when mailed to such address postage prepaid, registered or certified mail,
return receipt requested, or when delivered to such address by hand.

10.4 BIND AND INURE.

     The obligations of this Lease shall run with the land and this Lease shall
be binding upon and inure to the benefit of the parties hereto and their
respective successors and assigns, except that the Landlord named herein and
each successive owner of the Premises shall be liable only for the obligations
accruing during the period of its ownership. The obligations of Landlord shall
be binding upon the assets of Landlord which comprise the Premises but not upon
other assets of Landlord. No individual partner, trustee, stockholder, officer,
director, employee or beneficiary of Landlord shall be personally liable under
this Lease and Tenant shall look solely to Landlord's interest in the Premises
in pursuit of its remedies upon an event of default hereunder, and the general
assets of the individual partners, trustees, stockholders, officers, employees
or beneficiaries of Landlord

                                      -31-

 
shall not be subject to levy, execution or other enforcement procedure for the
satisfaction of the remedies of Tenant.

10.5 NO SURRENDER.

     The delivery of keys to any employee of Landlord or to Landlord's agent or
any employee thereof shall not operate as a termination of this Lease or a
surrender of the Premises.

10.6 NO WAIVER, ETC.

     The failure of Landlord or of Tenant to seek redress for violation of, or
to insist upon the strict performance of, any covenant or condition of this
Lease or, with respect to such failure of Landlord, any of the Rules and
Regulations referred to in Section 6.1.4, whether heretofore or hereafter
adopted by Landlord, shall not be deemed a waiver of such violation nor prevent
a subsequent act, which would have originally constituted a violation, from
having all the force and effect of an original violation, nor shall the failure
of Landlord to enforce any of said Rules and Regulations against any other
tenant in the Building be deemed a waiver of any such Rules or Regulations.  The
receipt by Landlord of Annual Rent or additional rent with knowledge of the
breach of any covenant of this Lease shall not be deemed a waiver of such breach
by Landlord, unless such waiver be in writing and signed by Landlord.  No
consent or waiver, express or implied, by Landlord or Tenant to or of any breach
of any agreement or duty shall be construed as a waiver or consent to or of any
other breach of the same or any other agreement or duty.

10.7 NO ACCORD AND SATISFACTION.

     No acceptance by Landlord of a lesser sum than the Annual Rent and
additional rent then due shall be deemed to be other than on account of the
earliest installment of such rent due, nor shall any endorsement or statement on
any check or any letter accompanying any check or payment as rent be deemed as
accord and satisfaction, and Landlord may accept such check or payment without
prejudice to Landlord's right to recover the balance of such installment or
pursue any other remedy in this Lease provided.

10.8 CUMULATIVE REMEDIES.

     The specific remedies to which Landlord may resort under the terms of this
Lease are cumulative and are not intended to be exclusive of any other remedies
or means of redress to which it may be lawfully entitled in case of any breach
or threatened breach by Tenant of any provisions of this Lease. In addition to
the other remedies provided in this Lease, Landlord shall be

                                      -32-

 
entitled to the restraint by injunction of the violation or attempted or
threatened violation of any of the covenants, conditions or provisions of this
Lease or to a decree compelling specific performance of any such covenants,
conditions or provisions.

10.9 LANDLORD'S RIGHT TO CURE.

     If Tenant shall at any time default in the performance of any obligation
under this Lease, Landlord shall have the right, but shall not be obligated, to
enter upon the Premises and to perform such obligation, notwithstanding the fact
that no specific provision for such substituted performance by Landlord is made
in this Lease with respect to such default.  In performing such obligation,
Landlord may make any payment of money or perform any other act.  All sums so
paid by Landlord (together with interest at the rate of 4% per annum in excess
of the then average prime commercial rate of interest being charged by the three
largest national banks in Boston, Massachusetts), and all necessary incidental
costs and expenses in connection with the performance of any such act by
Landlord, shall be deemed to be additional rent under this Lease and shall be
payable to Landlord immediately on demand.  Landlord may exercise the foregoing
rights without waiving any other of its rights or releasing Tenant from any of
its obligations under this Lease.

10.10     ESTOPPEL CERTIFICATE.

     Tenant agrees, from time to time, upon not less than fifteen (15) days'
prior written request by Landlord, to execute, acknowledge and deliver to
Landlord a statement in writing certifying that this Lease is unmodified and in
full force and effect; that Tenant has no defenses, offsets or counterclaims
against its obligations to pay the Annual Rent and additional rent and to
perform its other covenants under this lease; that there are no uncured defaults
of Landlord or Tenant under this Lease (or, if there have been modifications,
that this Lease is in full force and effect as modified and stating the
modifications and, if there are any defenses, offsets, counterclaims, or
defaults, setting them forth in reasonable detail); and the dates to which the
Annual Rent, additional rent and other charges have been paid. Any such
statement delivered pursuant to this Section 10.10 shall be in a form reasonably
acceptable to and may be relied upon by any prospective purchaser or mortgagee
of premises which include the Premises or any prospective assignee of any such
mortgagee.

                                      -33-

 
10.11     WAIVER OF SUBROGATION.

     Any insurance carried by either party with respect to the Premises and
property therein or occurrences thereon shall include a clause or endorsement
denying to the insurer rights of subrogation against the other party to the
extent rights have been waived by the insured prior to occurrences of injury or
loss.  Each party, notwithstanding any provisions of this Lease to the contrary,
hereby waives any rights of recovery against the other for injury or loss due to
hazards covered by insurance containing such clause or endorsement to the extent
of the indemnification received thereunder.

10.12     ACTS OF GOD.

     In any case where either party hereto is required to do any act (other than
the payment of rent), delays caused by or resulting from Acts of God, war, civil
commotion, fire, flood or other casualty, labor difficulties, shortages of
labor, materials or equipment, government regulations, unusually severe weather
or other causes beyond such party's reasonable control shall not be counted in
determining the time during which work shall be completed, whether such time be
designated by a fixed date, a fixed time or a "reasonable time," and such time
shall be deemed to be extended by the period of such delay.

10.13     BROKERAGE.

     Tenant represents and warrants that it has dealt with no broker in
connection with this transaction other than Meredith & Grew, Incorporated and
agrees to defend, with counsel approved by Landlord, indemnify and save Landlord
harmless from and against any and all cost, expense or liability for any
compensation, commissions or charges claimed by a broker or agent, other than
with Meredith & Grew, Incorporated, with respect to Tenant's dealings in
connection with this Lease.

10.14     SUBMISSION NOT AN OFFER.

     The submission of a draft of this Lease or a summary of some or all of its
provisions does not constitute an offer to lease or demise the Premises, it
being understood and agreed that neither Landlord nor Tenant shall be legally
bound with respect to the leasing of the Premises unless and until this Lease
has been executed by both Landlord and Tenant and a fully executed copy has been
delivered to each of them.

                                      -34-

 
10.15     APPLICABLE LAW AND CONSTRUCTION.

     This Lease shall be governed by and construed in accordance with the laws
of the state in which the Premises are located.  If any term, covenant,
condition or provision of this Lease or the application thereof to any person or
circumstances shall be declared invalid or unenforceable by the final ruling of
a court of competent jurisdiction having final review, the remaining terms,
covenants, conditions and provisions of this Lease and their application to
persons or circumstances shall not be affected thereby and shall continue to be
enforced and recognized as valid agreements of the parties, and in the place of
such invalid or unenforceable provision, there shall be substituted a like, but
valid and enforceable provision which comports to the findings of the aforesaid
court and most nearly accomplishes the original intention of the parties.

     There are no oral agreements between Landlord and Tenant affecting this
Lease.  The only written agreements between Landlord and Tenant other than this
Lease are (i) a letter agreement dated February 28, 1991 with respect to the
granting by Landlord to Tenant of a license to occupy certain storage space in
the Building (the "Letter Agreement"), (ii) a Lease dated February 28, 1991 and
(iii) a Lease dated June 11, 1992 as amended by a First Amendment to Lease dated
June 11, 1992 (the leases referred to in clauses (ii) and (iii) are hereinafter
referred to as the "Previous Leases").  As of the Commencement Date, the
Previous Leases, but not the Letter Agreement, shall be superseded by this Lease
and shall be deemed to be null and void, and either party, upon request of the
other party shall so certify.  This Lease may be amended, and the provisions
hereof may be waived and modified, only by instruments in writing executed by
Landlord and Tenant.

     The titles of the several Articles and Sections contained herein are for
convenience only and shall not be considered in construing this Lease.

     Unless repugnant to the context, the words "Landlord" and "Tenant"
appearing in this Lease shall be construed to mean those named above and their
respective heirs, executors, administrators, successors and assigns, and those
claiming through or under them respectively.  If there be more than one tenant,
the obligations imposed by this Lease upon Tenant shall be joint and several.

                                      -35-

 
     EXECUTED as a sealed instrument on the day and year first above written.

                                   LANDLORD:  L&E INVESTMENT OF
                                              MASSACHUSETTS ONE, INC.


                                   By: /s/ David C. Sherwood
                                      ----------------------------------- 


                                   TENANT:  CREDIT TECHNOLOGIES,  INC.


                                   By: /s/ Pamela D.A. Reeve
                                      -----------------------------------
                                      Pamela D.A. Reeve, Its President


                                   By: /s/ William G. Brown
                                      -----------------------------------
                                      William G. Brown, Its Treasurer
                                        and Vice President of Finance

                                      -36-

 
                                  EXHIBIT A-1
                                  -----------

 
                           [FLOOR PLAN APPEARS HERE]

 
                                  EXHIBIT A-2
                                  -----------

 
                           [FLOOR PLAN APPEARS HERE]

 
                                   EXHIBIT B
                                   ---------

 
                           [FLOOR PLAN APPEARS HERE]

 
                                   EXHIBIT C
                                   ---------
                               
                                Somerset Court
                               281 Winter Street
                            Waltham, Massachusetts
                               
                              BUILDING STANDARDS
                              ------------------

The Tenant will receive the following Tenant Improvements, which are included as
part of the Fixed Rent Rate.

1.   PARTITIONS:
     -----------

     a)  Demising partitions will be constructed of 3 5/8" metal studs with 5/8"
         gypsum wall board on each side. Demising partitions will extend from
         the finish floor to the underside of the floor deck above, subject to
         the requirements of the building and air conditioning system and the
         partition will be filled with 3" of fiberglass sound insulation.

     b)  Interior partitions will be constructed of 3 5/8" metal studs with 5/8"
         gypsum board on each side. Partitions will extend from the floor to the
         underside of the acoustical tile ceiling. Tenant allowance shall be as
         shown on attached Exhibit A.

2.   DOORS:
     ------

     a)  Each tenant will be allowed one entrance door of solid core oak, 3' x
         8'-4", with a door closer, lever handle mortise lock-set. Door frame
         will be natural finish oak.

     b)  Interior doors shall be 3' x 7' solid core oak in painted metal frames.
         Doors shall be finished natural with low sheen varnish and shall have
         80% lever latchsets. Tenant allowance shall be as shown on attached
         Exhibit A.

3.   PAINTING AND WALL COVERING:
     ---------------------------

     a)  All tenant partitions will receive two coats of latex paint. Color
         selection will be made from building standard samples with not more
         than one color per room. All partitions will have a 4" vinyl base.

                                      C-1

 
     b)  Wall covering will be provided at Tenant's own expense and shall be
         subject to Landlord's approval prior to installation.

4.   FLOORS:
     ------ 

     Carpet shall be thirty (30) ounce commercial grade installed from building
     standard samples or from Landlord approved selection provided by Tenant.
     Vinyl tile may be substituted for carpet as required.

5.   CEILING:
     ------- 

     Ceilings will be 2' x 2' acoustic lay-in Armstrong Cortega Minaboard or
     equal tile. Ceiling height will be 8'-6".

6.   ELECTRICAL:  (as shown on attached PLAN A)
     ----------                                

          Device                                     Description
          ------                                     -----------

     Lighting Fixtures                           2' x 4' Parabolic

     Wall Switches                               Single Pole

     Electrical Outlets                          120v Duplex Wall Mount

7.   TELEPHONE:
     --------- 

     Wall telephone outlets will be provided as shown on attached Exhibit A and
     will consist of a cut out in the drywall partition with a pull string
     inside the partition to above the ceiling. Installation of all telephone
     wiring, which shall meet the requirements of the Massachusetts Electrical
     Code and the local building and electrical inspectors, is the
     responsibility of Tenant.

8.   SUN CONTROL BLINDS:
     ------------------ 

     a)   All windows will be 1" bronze insulated glass.

     b)   All perimeter windows will be provided with operable vertical
          Louverdrape blinds in building standard color.

9.   SPRINKLERS:
     ---------- 

     General office space shall have flushed mounted sprinkler heads as required
     by local laws and ordinances.

                                      C-2

 
10.  HEATING AND AIR CONDITIONING:
     ----------------------------

     Cooling shall be provided from a central mechanical plant in the penthouse
     through a medium pressure manifold variable volume duct system.  Heating
     shall be provided with constant volume fan coil units or induction units
     connected to the duct system and installed in the ceiling plenum.

     Space thermostats and separate zones will be provided for approximately
     each 50 lineal feet of building perimeter and approximately each 2,500
     square feet of interior space.

     Supply air shall be provided through linear diffusers near the windows for
     the exterior zones and through slot diffusers for interior zones.

11.  MISCELLANEOUS:
     --------------

     a)   Each floor will have a drinking fountain accessible to all tenants.

     b)   Showers will be located in the second floor Men's and Women's toilet
          facilities.

All improvements not stated above will be provided by Tenant at its own expense.
Such improvements will be approved by Landlord prior to installation.

                                      C-3

 
                                   EXHIBIT D
                                   ---------

                                Somerset Court
                               281 Winter Street
                            Waltham, Massachusetts

                              LANDLORD'S SERVICES
                              -------------------


I.   CLEANING

     A.   General

     1.   All cleaning work will be performed between 8 a.m. and 12 midnight,
          Monday through Friday, unless otherwise necessary for stripping,
          waxing, etc.

     2.   Abnormal waste removal (e.g., computer installation paper, bulk
          packaging, wood or cardboard crates, refuse from cafeteria operation,
          etc.) shall be Tenant's responsibility.

     B.   Daily Operations (5 times per week)

          1.   Tenant Areas

               a.   Empty and clean all waste receptacles; wash receptacles as
                    necessary.
               b.   Vacuum all rugs and carpeted areas.
               c.   Empty, damp-wipe and dry all ashtrays.

          2.   Lavatories

               a.   Sweep and wash floors with disinfectant.
               b.   Wash both sides of toilet seats with disinfectant.
               c.   Wash all mirrors, basins, bowls, urinals.
               d.   Spot clean toilet partitions.
               e.   Empty and disinfect sanitary napkin disposal receptacles.
               f.   Refill toilet tissue, towel, soap, and sanitary napkin
                    dispensers.

          3.   Public Areas

               a.   Wipe down entrance doors and clean glass (interior and
                    exterior).
               b.   Vacuum elevator carpets and wipe down doors and walls.
               c.   Clean water coolers.

                                      D-1

 
     C.   Operations as Needed (but not less than every other day)

          1.   Tenant and Public Areas

               a.   Buff all resilient floor areas.

     D.   Weekly Operations

          1.   Tenant Areas, Lavatories, Public Areas

               a.   Hand-dust and wipe clean all horizontal surfaces with
                    treated cloths to include furniture, office equipment,
                    windowsills, door ledges, chair rails, baseboards, convector
                    tops, etc., within normal reach.
               b.   Remove finger marks from private entrance doors, light
                    switches, and doorways.
               c.   Sweep all stairways.

     E.   Monthly Operations

          1.   Tenant and Public Areas

               a.   Thoroughly vacuum seat cushions on chairs, sofas, etc.
               b.   Vacuum and dust grillwork.

          2.   Lavatories

               a.   Wash down interior walls and toilet partitions.

     F.   As Required and Weather Permitting

          1.   Entire Building

               a.   Clean inside of all windows.
               b.   Clean outside of all windows.

     G.   Yearly

          1.   Tenant and Public Areas

               a.   Strip and wax all resilient tile floor areas.
               b.   Shampoo carpet in common facilities as necessary in
                    Landlord's sole discretion.

                                      D-2

 
II.  HEATING, VENTILATING, AND AIR CONDITIONING

     1.   Heating, ventilating, and air conditioning as required to provide
          reasonably comfortable temperatures for normal business day occupancy
          (excepting holidays); Monday through Friday from 8:00 a.m. to 5:00
          p.m. and Saturday from 8:00 a.m. to 1:00 p.m.

     2.   Maintenance of any additional or special air conditioning equipment
          and the associated operating cost will be at Tenant's expense.

III. WATER

     Hot water for lavatory purposes and cold water for drinking, lavatory and
     toilet purposes.

IV.  ELEVATORS (if Building is Elevatored)

     Elevators for the use of all tenants and the general public for access to
     and from all floors of the Building.
     Programming of elevators (including, but not limited to, service elevators)
     shall be as Landlord from time to time determines best for the Building as
     a whole.

V.   RELAMPING OF LIGHT FIXTURES

     Tenant will reimburse Landlord for the cost of lamps, ballasts and starters
     and the cost of replacing same within the Premises.

VI.  CAFETERIA AND VENDING INSTALLATIONS

     1.   Any space to be used primarily for lunchroom or cafeteria operation
          shall be Tenant's responsibility to keep clean and sanitary, it being
          understood that Landlord's approval of such use must be first obtained
          in writing.

     2.   Vending machines or refreshment service installations by Tenant must
          be approved by Landlord in writing and shall be restricted in use to
          employees and business callers.  All cleaning necessitated by such
          installations shall be at Tenant's expense.

VII. Electricity

     A.   Landlord, at Landlord's expense, shall furnish electrical energy
          required for lighting, electrical 

                                      D-3

 
          facilities, equipment, machinery, fixtures, and appliances used in or
          for the benefit of Tenant's Space, in accordance with the provisions
          of the Lease of which this Exhibit is part.

     B.   Tenant shall not, without prior written notice to Landlord in each
          instance, connect to the Building electric distribution system any
          fixtures, appliances or equipment other than normal office machines
          such as desk-top calculators and typewriters, or any fixtures,
          appliances or equipment which Tenant on a regular basis operates
          beyond normal building operating hours.  In the event of any such
          connection, Tenant agrees to an increase in the ANNUAL ESTIMATED
          ELECTRICAL COST TO TENANT'S SPACE and a corresponding increase in
          Annual Rent by an amount which will reflect the cost to Landlord of
          the additional electrical service to be furnished by Landlord, such
          increase to be effective as of the date of any such installation.  If
          Landlord and cannot agree thereon, such amount shall be conclusively
          determined by a reputable independent electrical engineer or
          consulting firm to be selected by Landlord and paid equally by both
          parties, and the cost to Landlord will be included in Landlord's
          Operating Costs provided in Section 4.2 hereof.

     C.   Tenant's use of electrical energy in Tenant's Space shall not at any
          time exceed the capacity of any of the electrical conductors or
          equipment in or otherwise serving Tenant's Space.  In order to insure
          that such capacity is not exceeded and to avert possible adverse
          effect upon the Building electric service, Tenant shall not, without
          prior written notice to Landlord in each instance, connect to the
          Building electric distribution system any fixtures, appliances or
          equipment which operate on a voltage in excess of 120 volts nominal or
          make any alteration or addition to the electric system of Tenant's
          Space.  Unless Landlord shall reasonably object to the connection of
          any such fixtures, appliances or equipment, all additional risers or
          other equipment required therefor shall be provided by Landlord, and
          the cost thereof shall be paid by Tenant upon Landlord's demand.  In
          the event of any such connection, Tenant agrees to an increase in the
          ANNUAL ESTIMATED ELECTRICAL COST TO TENANT'S SPACE and a corresponding
          increase in Annual Rent by an amount which will reflect the cost to
          Landlord of the additional service to be furnished by Landlord, such
          increase to be effective as of the date of any such connection.  If
     
                                      D-4

 
          Landlord and Tenant cannot agree thereon, such amount shall be
          conclusively determined by a reputable independent electrical engineer
          or consulting firm to be selected by Landlord and paid equally by both
          parties, and the cost to Landlord will be included in Landlord's
          Operating Costs provided in Section 4.2 hereof.

     D.   If at any time after the date of this Lease, the rates at which
          Landlord purchases electrical energy from the public utility supplying
          electric service to the Building, or any charges incurred or taxes
          payable by Landlord in connection therewith, shall be increased or
          decreased, the Annual Rent and ANNUAL ESTIMATED ELECTRICAL COST TO
          TENANT'S SPACE shall be increased or decreased, as the case may be, by
          an amount equal to the estimated increase or decrease, as the case may
          be, in Landlord's cost of furnishing the electricity referred to in
          Paragraph A above as a result of such increase or decrease in rates,
          charges, or taxes. If Landlord and Tenant cannot agree thereon, such
          amount shall be conclusively determined by a reputable independent
          electrical engineer or consulting firm to be selected by Landlord and
          paid equally by both parties, and the cost to Landlord will be
          included in Landlord's Operating Costs as provided in Section 4.2
          hereof. Any such increase or decrease shall be effective as of the
          date of the increase or decrease in such rate, charges, or taxes.

     E.   Landlord may, at any time, elect to discontinue the furnishing of
          electrical energy.  In the event of any such election by Landlord: (1)
          Landlord agrees to give reasonable advance notice of any such
          discontinuance to Tenant; (2) Landlord agrees to permit Tenant to
          receive electrical service directly from the public utility supplying
          service to the Building and to permit the existing feeders, risers,
          wiring and other electrical facilities serving Tenant's Space to be
          used by Tenant and/or such public utility for such purpose to the
          extent they are suitable and safely capable; (3)   Landlord agrees to
          pay such charges and costs, if any, as such public utility may impose
          in connection with the installation of Tenant's meters and to make or,
          at such public utility's election, to pay for such other installations
          as such public utility may require, as a condition of providing
          comparable electrical service to Tenant; (4) the Annual Rent shall be
          equitably decreased to reflect such discontinuance by an amount equal
          to the ANNUAL ESTIMATED ELECTRICAL COST TO TENANT'S SPACE then 

                                      D-5

 
          in effect; and (5) Tenant shall thereafter pay, directly to the
          utility furnishing the same, all charges for electrical services to
          the Premises.

     F.   Whenever the Annual Rent is increased or decreased pursuant to any of
          the foregoing paragraphs of this Article, the parties agree, upon
          request of either, to execute and deliver each to the other an
          amendment to this Lease confirming such increase or decrease.

                                      D-6

 
                                   EXHIBIT E
                                   ---------
                                
                                Somerset Court
                               281 Winter Street
                             Waltham, Massachusetts

                             RULES AND REGULATIONS
                             ---------------------


1.   The entrance, lobbies, passages, corridors, elevators and stairways shall
     not be encumbered or obstructed by Tenant, Tenant's agents, servants,
     employees, licensees or visitors or be used by them for any purpose other
     than for ingress and egress to and from the Premises.  The moving in or out
     of all sales, freight, furniture or bulky matter of any description must
     take place during the hours which Landlord may determine from time to time.
     Landlord reserves the right to inspect all freight and bulky matter to be
     brought into the Building and to exclude from the Building all freight and
     bulky matter which violates any of these Rules and Regulations or the Lease
     of which these Rules and Regulations are a part.

2.   No curtains, blinds, shades, screens or signs other than those furnished by
     Landlord shall be attached to, hung in or used in connection with any
     window or door of the Premises without the prior written consent of
     Landlord.  Interior signs on doors shall be painted or affixed for Tenant
     by Landlord or by sign painters first approved by Landlord at the expense
     of Tenant and shall be of a size, color and style acceptable to Landlord.

3.   No additional locks or bolts of any kind shall be placed upon any of the
     doors or windows by Tenant, nor shall any changes be made in existing locks
     or the mechanism thereof without the prior written consent of Landlord.
     Tenant must, upon the termination of its tenancy, restore to Landlord all
     keys of stores, shops, booths, stands, offices and toilet rooms, either
     furnished to or otherwise procured by Tenant, and in the event of the loss
     of any keys so furnished, Tenant shall pay to Landlord the cost thereof.

4.   Canvassing, soliciting and peddling in the Building are prohibited and
     Tenant shall cooperate to prevent the same.

5.   Tenant may request heating and/or air conditioning during other periods in
     addition to normal working hours by submitting its request in writing to
     the Building Manager's office not later than 2 p.m. the preceding workday
     (Monday through Friday) on forms available from the Building Manager.  

                                      E-1

 
     The request shall clearly state the start and stop hours of the "off-hour"
     service. Tenant shall submit to the Building Manager a list of personnel
     who are authorized to make such requests. Charges are to be determined by
     the Building Manager on the additional hours of operations and shall be
     fair and reasonable and reflect the additional operating costs involved.

6.   Tenant shall comply with all security measures from time to time
     established by Landlord for the Building.

7.   Tenant shall be responsible for causing its visitors to park only in spaces
     or areas marked "Visitors Parking" and Tenant and its employees shall not
     park in spaces or areas marked "Visitor Parking" or "No Parking".  Landlord
     reserves the right to tow any cars parked in "Visitor Parking" or "No
     Parking" areas in violation of these rules and regulations at the sole
     expense of the owner of the improperly parked car.  Landlord reserves the
     right to designate reserved parking spaces for the Building's tenants.  If
     any parking spaces are designated as reserved for Tenant, Tenant and its
     employees shall park only in those parking spaces which have been reserved
     for Tenant and in those unmarked parking spaces which Tenant has the right
     to use in common with other tenants.  Tenant is responsible for policing
     any parking spaces reserved solely for its use and may tow any cars
     improperly parked in such reserved parking spaces.  Such towing must be
     done by a company approved by Landlord.  Tenant agrees, upon the request of
     Landlord, to provide Landlord with the license plate number and make and
     model of each of the cars which will be used by Tenant and its employees
     and shall specify which cars will be using the parking spaces reserved
     solely for Tenant's use.  Landlord is entitled to rely on the information
     provided to it by Tenant and need not make any further inquiry into the
     ownership of the cars on the Lot.  Violations of this Rule No. 7 shall be
     considered a default under the Tenant's lease and Landlord shall have all
     rights contained therein with respect to a default by Tenant.

                                      E-2

 
                                   EXHIBIT F
                                   ---------

                           MANDATORY EXPANSION SPACE
                           -------------------------

                                      F-1

 
                           [FLOOR PLAN APPEARS HERE]

 
                            FIRST AMENDMENT TO LEASE

     This First Amendment to Lease is entered into as of the 31st day of May,
19-94 by and between L & E INVESTMENT OF MASSACHUSETTS ONE, INC., a Delaware
corporation (the "Landlord"), and CREDIT TECHNOLOGIES, INC., a Delaware
corporation (the "Tenant").

                                R E C I T A L S
                                - - - - - - - -

     WHEREAS, Landlord and Tenant have entered into that certain Lease dated
September 21, 1993, (the "Lease") with respect to certain premises located in
the building ("Building") known and numbered as 281 Winter Street, Waltham,
Massachusetts and more particularly described in said Lease (the "Premises");

     WHEREAS, in accordance with Section 2.5 of the Lease Landlord has offered
to lease to Tenant and Tenant has accepted from Landlord 1,089 square feet of
space on the first floor of the Building, all as more fully set forth herein;
and

     WHEREAS, Landlord and Tenant therefore wish to amend the Lease in order to
reflect such expansion, subject to the terms and conditions set forth below;

     NOW, THEREFORE for good and valuable consideration the receipt and
sufficiency of which are hereby acknowledged, Landlord and Tenant hereby agree
as follows:

     1.   All capitalized terms used herein and not otherwise defined shall have
the meaning ascribed to such term in the Lease.

     2.   Effective as of August 1, 1994 the parties agree that 1,809 square
feet of adjacent space on the first floor of the Building (the "Expansion
Space") shall be added to the Premises and the definition of the term "TENANT'S
SPACE" set forth in Section 1.1 of the Lease shall be and hereby is amended by
deleting the first floor space plan attached as Exhibit A1 to the Lease and
substituting therefore the first floor space plan attached as Exhibit A1 to the
Lease and substituting therefore the first floor space plan attached as Exhibit
A1 to this Amendment.  Thereafter, all references to "Premises" or "Tenant's
Space" contained in the Lease shall be read to refer to the original 17,580
square feet together with the Expansion Space being added by this Amendment and
the terms and provisions of the Lease, as the same may be amended hereby, shall
apply to said Expansion Space as fully as if it had been included in the
Premises originally demised, including without limitation those terms relating
to the payment of fixed and additional rent.

 
     3.   Effective as of August 1, 1994 the definition of the term "RENTABLE
FLOOR OF TENANT'S SPACE: set forth in Section 1.1 of the Lease is hereby deleted
and the following is substituted therefore;

          "RENTABLE FLOOR AREA OF TENANT'S SPACE: 19,389 square
          feet (14,691 of which are on the first floor and 4,698
          of which are on the second floor), as the same may be
          increased pursuant to the terms hereof."

     4.   Effective as of August 1, 1994 the definition of the term "TENANT'S
PROPORTIONATE SHARE" set forth in Section 1.1 of the Lease is hereby amended by
deleting the phrase "25.93% (17,580 square feet divided by 67,800 square feet)"
and substituting "28.60% (19,389 square feet divided by 67,800 square feet)"
therefor.

     5.   Effective as of August 1, 1994 the definition of "PARKING  SPACES
ALLOCATED TO TENANT" set forTh in Section 1.1 of the Lease is hereby amended by
deleting the phrase "Approximately 70 parking spaces" and substituting
"Approximately 78 parking spaces" therefor.

     6.   Landlord hereby agrees that on or before August 1, 1994 it remove the
existing demising wall separating the Expansion Space the original 17,580 square
feet premises, and Landlord agrees to use diligent efforts to ensure that
Tenant's use of the Premises is not unreasonably disrupted by such demolition.
Landlord further agrees that it will patch and paint the walls of the Expansion
Space in accordance with building standards.

     7.   Tenant represents and warrants that it has dealt with no broker in
connection with this Amendment other than Meredith & Grew, incorporated and
agrees to defend, with counsel approved by Landlord, indemnify and save Landlord
harmless from and against any and all cost, expense or liability for any
compensation, or charges claimed by a broker or agent, other than with Meredith
& Grew, Incorporated, with respect to Tenant's dealings in connection with this
Amendment.

     8.   The terms and provisions of the Lease, as modified by this Amendment,
are hereby ratified and confirmed and the parties agree that said Lease, as so
modified, remains in full force and effect.

                                       2

 
     EXECUTED under seal this as of the date first above written.

                                        LANDLORD:

                                        L & E INVESTMENT OF
                                        MASSACHUSETTS ONE, INC.



                                        By: /s/ David C. Sherwood
                                           --------------------------------
                                           Name: DAVID C. SHERWOOD       
                                           Its:  CEO

                                        TENANT:
                                        
                                        CREDIT TECHNOLOGIES, INC.


                                        By: /s/ William G. Brown
                                           --------------------------------
                                           Name: WILLIAM G. BROWN
                                           Its:  VICE PRESIDENT - FINANCE

                                       3

 
                           [FLOOR PLAN APPEARS HERE]