AMENDED AND RESTATED EMPLOYMENT AGREEMENT


This Amended and Restated Employment Agreement (the "Agreement") is entered into
as of the 17th day of  February,  1999,  by and  between  Michael D. Kallet (the
"Employee") and ICG PST, Inc.  (formerly  known as Netcom On-Line  Communication
Services, Inc.), a Delaware corporation (the "Corporation").

WHEREAS,  Corporation  and Employee  entered into an Employment  Agreement dated
June 1, 1997 as  modified  by a letter  dated  November  20,  1998  (the  "First
Employment Agreement"), and

WHEREAS,  Corporation  and  Employee  desire  to amend  and  restate  the  First
Employment Agreement.

NOW THEREFORE, the parties agree as follows :

For ease of reference, this Agreement is divided into the following parts, which
begin on the pages indicated:

FIRST PART:                TERM OF EMPLOYMENT, DUTIES AND SCOPE, COMPENSATION
                           AND BENEFITS DURING EMPLOYMENT
                           (Sections 1-5, beginning on page 2)

SECOND PART:               COMPENSATION AND BENEFITS IN CASE OF ACTUAL OR 
                           CONSTRUCTIVE TERMINATION (Sections 6-9,
                           beginning on page 6)

THIRD PART:                PARACHUTE PAYMENTS
                           (Sections 10-11, beginning on page 8)

FOURTH PART:               TRADE SECRETS, SUCCESSORS, MISCELLANEOUS PROVISIONS, 
                           SIGNATURE PAGE (Sections 12-15,
                           beginning on page 11)


                                       1



FIRST PART:                TERM OF EMPLOYMENT, DUTIES AND SCOPE, COMPENSATION 
                           AND BENEFITS DURING EMPLOYMENT

Section 1:  Term of Employment

(a)  Basic Rule: The Corporation  agrees to continue the Employee's  employment,
     and the Employee agrees to remain in employment with the Corporation,  from
     February 15, 1999, until the earliest of:

     (1)  The date of the Employee's death; or

     (2)  The  date  when  the  Employee's  employment  terminates  pursuant  to
          Subsection (b), (c), (d) and (e) below.

(b)  Early  Termination  or  Resignation.  The  Corporation  may  terminate  the
     Employee's employment at any time and for any reason by giving the Employee
     written  notice.  The Employee may terminate the Employee's  employment for
     any reason by giving the  Corporation not less than 30 days' advance notice
     in writing.

(c)  Termination  for  Cause.  The  Corporation  may  terminate  the  Employee's
     employment  at any  time for  Cause  shown.  For all  purposes  under  this
     Agreement,  "Cause"  shall mean (1) a willful  failure by the  Employee  to
     substantially  perform the Employee's  duties under this  Agreement,  other
     than a failure resulting from the Employee's complete or partial incapacity
     due to physical or mental illness or  impairment,  (2) a willful act by the
     Employee that constitutes gross misconduct and that is materially injurious
     to the  Corporation,  (3) a willful  breach by the  Employee  of a material
     provision of this  Agreement  or (4) a material and willful  violation of a
     federal  or state  law or  regulation  applicable  to the  business  of the
     Corporation   that  is  materially  and   demonstrably   injurious  to  the
     Corporation. No act, or failure to act, by the Employee shall be considered
     "willful"  unless  committed  without  good faith and without a  reasonable
     belief that the act or omission was in the Corporation's best interest.

(d)  Termination  for  Disability.  The Corporation may terminate the Employee's
     employment for Disability by giving the Employee  written  notice.  For all
     purposes under this Agreement,  "Disability"  shall mean that the Employee,
     at the time the notice is given,  has been unable to perform the Employee's
     duties under this Agreement for a period of not less than three consecutive
     months as a result of the  Employee's  incapacity due to physical or mental
     illness.  In the  event  that  the  Employee  resumes  the  performance  of
     substantially  all of the Employee's duties under this Agreement before the
     termination  of  the  Employee's  employment  under  this  Section  becomes
     effective,  the notice of termination shall automatically be deemed to have
     been revoked.

(e)  Termination of Agreement.  This Agreement shall expire when all obligations
     of the parties  hereunder  have been  satisfied.  In  addition,  either the
     Corporation  or the Employee may terminate  this  Agreement for any reason,
     and without affecting the Employee's  status as an employee,  by giving the
     other party one year's  advance  notice in writing.  A termination  of this
     Agreement  pursuant to the  preceding  sentence  shall be effective for all
     purposes,  except  that such  termination  shall not affect the  payment or
     provision of  compensation or benefits under this Agreement on account of a

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     termination  of  employment  occurring  prior  to the  termination  of this
     Agreement.

Section 2:  Duties and Scope of Employment

(a)  Position.  The  Corporation  agrees to employ the  Employee for the term of
     employment  under this  Agreement in the position of Senior Vice  President
     and General Manager and Chief Operating  Officer and the duties  associated
     with this position.

     These  duties  will  include  the overall  management  of the  Corporation,
     including  responsibility  for the P&L of the company and product planning,
     marketing,  operations,  engineering,  R&D,  customer  service and support.
     Duties also include  responsibility  of sales in conjunction with the Sales
     team managed out of the Telecom Group. The company's business is focused on
     the inter-exchange  data networking  business,  supplying ISPs, Telecom and
     other end-user  customers with network  backbone,  network related products
     that extend outside of the  telecom-switch  central office, and other value
     add data services,  including but not limited to Voice over IP (VOIP),  and
     other IP services.  This  includes  the  definition,  creation,  marketing,
     selling,  operating and supporting of these services along with the product
     road map.

     Employee agrees that neither assuming the title nor the duties described in
     this Section 2 shall result in a Constructive Termination under this or the
     First Employment Agreement.

(b)  Obligations.  During  the term of  employment  under  this  Agreement,  the
     Employee shall devote the Employee's full business  efforts and time to the
     business and affairs of the  Corporation  as needed to carry out his duties
     and  responsibilities  hereunder subject to the overall  supervision of the
     Corporation's Chief Executive Officer or President. The foregoing shall not
     preclude the Employee from  engaging in  appropriate  civic,  charitable or
     religious  activities  or from  devoting  a  reasonable  amount  of time to
     private  investments  or from  serving on the boards of  directors of other
     entities,  as long as such  activities  and  service  do not  interfere  or
     conflict with the Employee's responsibilities to the Corporation.

Section 3:  Base Compensation, Employee Bonus

(a)  Effective  during  the  term  of  employment  under  this  Agreement,   the
     Corporation  agrees to pay the Employee as compensation for services a base
     salary  at the  annual  rate of  $220,000,  or at such  higher  rate as the
     authorized  Corporation  corporate  officer(s)  may determine  from time to
     time. Such salary shall be payable in accordance with the standard  payroll
     procedures of the  Corporation.  Once the authorized  corporate  officer(s)
     have increased such salary,  it thereafter shall not be reduced;  provided,
     however,  that if a  Change  in  Control  has  not  occurred,  such  salary
     (including  any  increases)  may be reduced by the  Corporation  if (1) the
     Employee  commits an act or omission that meets the definition of Cause, as
     defined  in  Section  1(c),  or (2) the  Employee  and all other  executive
     officers  of  the  corporation  who  are  parties  to  written   employment
     agreements  containing  substantially the same provisions as this Agreement
     have  their  salaries   (including  any  increases)  reduced  by  the  same
     percentage  amount  for the  same  time  period.  The  annual  compensation
     specified  in this  Section  3(a),  together  with  any  increases  in such

                                       3



     compensation that the authorized  corporate  officer(s) may grant from time
     to time,  and together with any  reductions  made in  accordance  with this
     Section 3, is referred to in this Agreement as "Base Compensation".

(b)  In addition to the Base  Compensation  described in Section 3(a),  Employee
     shall be eligible to receive an  incentive  bonus not to exceed  forty-five
     percent (45%) of Employee's  base salary (the  "Employee  Bonus").  Seventy
     percent of the  Employee  Bonus  shall be based on the  performance  of the
     Corporation.  Thirty  percent  of the  Employee  Bonus  shall  be  based on
     Employee's  individual  performance.  Specific bonus amounts as well as the
     standards  to measure  the  Corporation's  performance  and the  Employee's
     performance  will  defined by the  Corporation  in writing and agreed to by
     Employee.  Performance  objectives will be set and measured quarterly,  and
     bonus paid in accordance with the ICG  Communications,  Inc.  ("ICG") bonus
     payment schedule.

Section 4:  Employee Benefits, Stock Options

(a)  In  General.  During  the term of  employment  under  this  Agreement,  the
     Employee shall be eligible to participate in all employee benefit plans and
     executive  compensation  programs maintained by the Corporation,  including
     (without limitation) savings or profit-sharing plans, deferred compensation
     plans,  stock  option,  incentive or other bonus plans,  life,  disability,
     health, accident and other insurance programs, paid vacations,  and similar
     plans or programs,  subject in each case to the generally  applicable terms
     and conditions of the plan or program in question and to the discretion and
     determinations of any person,  committee or entity  administering such plan
     or program.

     In the event Corporation  adopts a phantom stock plan (or any other similar
     compensation or benefit plan for selected employees of the Corporation that
     is based upon or  calculated  with  reference to the stock or securities of
     ICG,  whether  or  not  it  actually  involves  the  sale  or  issuance  of
     securities),   Employee  shall   participate   in  such  plan.   Employee's
     Participation   in  the  plan  shall  include  a  percentage  of  stock  or
     compensation that is no less than any other PST operating executive.

(b)  Within  thirty  (30) days after this  Agreement  has been  executed by both
     parties,  Corporation shall request that the ICG Board of Directors approve
     issuing  Employee options for 25,000 shares of ICG common stock pursuant to
     the terms and conditions of the 1998 ICG Stock Option Plan.

(c)  The parties  acknowledge  that all stock options  granted to Employee under
     the Netcon  On-Line  Communication  Services,  Inc.  1993 Stock Option Plan
     (Amended  and  Restated  as of  January  23,  1997)  have been  vested.  If
     Employee's  employment  terminates  for  any  reason  including  Employee's
     resignation, solely for purposes of determining exercisability of the stock
     options under the applicable stock option plans, the Employee's termination
     date shall be  considered  to be nine (9) months  after the actual  date of
     termination  (the  "Stock  Option  Termination  Date").  Employee  will  be
     entitled to exercise his vested stock  options on or before the  expiration
     of 90 days after the Stock Option  Termination  Date in accordance with the
     stock option  agreements  under which the grants were made.  Employee shall
     have no rights as to vested  options not exercised  prior to the expiration
     of 90 days after the Stock Option Termination Date.

                                       4


(d)  In  addition,  in the event of a Change of  Control as defined in Section 9
     below, 50% of the original amount of all options (or the remaining unvested
     options,  if less than 50%)  granted to Employee  under ICG's stock  option
     plan(s), shall vest upon the effective date of the Change in Control.

(e)  Notwithstanding  anything in this Agreement or the applicable  stock option
     plan(s)  to the  contrary,  in the  event  Employee's  employment  with the
     Corporation is terminated in a Qualifying Termination as defined in Section
     7(a) of the  Agreement,  then all stock options  granted to Employee by the
     Corporation,  and all options  granted to Employee under ICG's stock option
     plan,  shall become vested and  exercisable on the date of such  Qualifying
     Termination. In addition, solely for purposes of determining exercisability
     the stock options under the applicable  stock option plans,  the Employee's
     termination date shall be considered to be nine (9) months after the actual
     date of termination (the "Stock Option Termination Date"). Employee will be
     entitled to exercise his vested stock  options on or before the  expiration
     of 90 days after the Stock Option  Termination  Date in accordance with the
     stock option  agreements  under which the grants were made.  Employee shall
     have no rights as to vested  options not exercised  prior to the expiration
     of 90 days after the Stock Option Termination Date.

Section 5:  Business Expenses and Travel

During  the term of  employment  under this  Agreement,  the  Employee  shall be
authorized to incur  necessary and reasonable  travel,  entertainment  and other
business  expenses in  connection  with the  Employee's  duties  hereunder.  The
Corporation  shall reimburse the Employee for such expenses upon presentation of
an itemized account and appropriate supporting documentation,  all in accordance
with generally applicable policies.

SECOND PART: COMPENSATION AND BENEFITS IN CASE OF ACTUAL OR 
             CONSTRUCTIVE TERMINATION.

Section 6:  

This Second Part of the Agreement, consisting of Sections 6 through 8, describes
the  benefits  and  compensation,  if any,  payable  in case of  termination  of
employment.

Section 7:  Involuntary  Actual or  Constructive  Termination  Without  Cause or
Disability.

In the event that, during the term of this Agreement,  the Employee's employment
terminates  in a Qualifying  Termination,  as defined in Subsection  (a),  then,
after  executing the release of claims  described in Section 7(d),  the Employee
shall be entitled to receive the payments and benefits  described in Subsections
(b) and (c).

(a)  Qualifying Termination. A Qualifying Termination occurs if:

     (1)  The  Corporation  terminates the Employee's  employment for any reason
          other than Cause or Disability; or


     (2)  The  Employee  separates  from  employment  with  the  Corporation  in
          response to a  "Constructive  Termination"  which means a reduction or
          material  change  in  salary,  benefits,  title,  positions,   duties,
          responsibilities,  powers and reporting  structure,  or requirement to
 

                                       5


          relocate,  except for office  locations  that would not  increase  the
          Employee's one-way commute distance by more than twenty (20) miles.

(b)  Severance (1x payment). The Corporation shall pay to the Employee following
     the date of the employment  termination  and over the succeeding 12 months,
     in accordance with standard payroll  procedures (or in a single,  lump some
     payment due at the time of such  termination if  termination  occurs within
     six months  after a Change in  Control  as defined in Section 9 below),  an
     amount equal to the following:

     (1)  One times the Employee's  Base  Compensation  in effect on the date of
          the employment termination; plus

     (2)  100% of the greater of the  Employee's  prior year's annual  incentive
          bonus or the Employee's  annual  incentive bonus earned on a quarterly
          basis as of the date of the  termination,  assuming  the  Employee was
          employed  on the  last day of the  quarter  in  which  termination  of
          employment occurred.

          Any  other  provision  of  this  Agreement  or  of  the  Corporation's
          incentive Bonus Plan  notwithstanding,  after the amount  described in
          this Subsection (b) has been paid to the Employee,  the Employee shall
          have no further interest in such Plan.

(c)  Twelve  Months of Life  Insurance  and Health Plan  Coverage.  The coverage
     described  in this  Subsection  (c) shall be provided  for a  "Continuation
     Period" beginning on the date when the employment  termination is effective
     and ending on the earlier of (1) the 12-month  anniversary of the date when
     the  employment  termination is effective or (2) the date of the Employee's
     death. During the Continuation  Period, the Employee (and, when applicable,
     the Employee's  dependents) shall be entitled to continue  participation in
     the  group  term  life  insurance  plan  and in the  health  care  plan for
     employees  maintained by the  Corporation  as if the Employee were still an
     employee of the  Corporation.  The coverage  provided under this Subsection
     (c)  shall  run   concurrently   with  and  shall  be  offset  against  any
     continuation  coverage  under Part 6 of Title I of the Employee  Retirement
     Income Security Act of 1974, as amended.  Where applicable,  the Employee's
     compensation  for purposes of such plans shall be deemed to be equal to the
     Employee's compensation (as defined in such plans) in effect on the date of
     the employment  termination.  To the extent that the  Corporation  finds it
     undesirable to cover the Employee under the group life insurance and health
     plans of the  Corporation,  the Corporation  shall provide the Employee (at
     its own expense) with the same level of coverage under individual policies.

(d)  Release of Claims.  As a  condition  to the  receipt  of the  payments  and
     benefits  described in this  Section 7, the  Employee  shall be required to
     execute a release of all claims arising out of the Employee's employment or
     the  termination  thereof  including,  but not  limited  to,  any  claim of
     discrimination  under  state or  federal  law,  but  excluding  claims  for
     indemnification  from the Corporation under any  indemnification  agreement
     with the  Corporation,  its  certificate  of  incorporation  and by-laws or
     applicable law or claims for directors and officers' insurance coverage.

                                       6


(e)  Conditions  to Receipt of  Payments  and  Benefits.  In view of  Employee's
     position and his access to Confidential Information,  as a condition to the
     receipt of payments and benefits  described in this Section 7, the Employee
     shall  not,  without  the  Corporation's   written  consent,   directly  or
     indirectly,  alone  or as a  partner,  joint  venture,  officer,  director,
     employee,  consultant,  agent or  stockholder  (other  than a less  than 5%
     stockholder of a publicly  traded company) (i) engage in any activity which
     is in  competition  with the  business,  the  products  or  services of the
     Corporation (a list of competitors and  competitive  products and services,
     which  may  be  updated,  is  attached  hereto);  (ii)  solicit  any of the
     Corporation's  employees,  consultants or customers,  (iii) hire any of the
     Corporation's  employees or consultants  in an unlawful  manner or actively
     encourage  employees  or  consultants  to leave  the  Corporation,  or (iv)
     otherwise breach his Confidential Information obligations.

(f)  No Mitigation. The Employee shall not be required to mitigate the amount of
     any payment or benefit  contemplated  by this Section 7, nor shall any such
     payment or benefit be reduced by any earnings or benefits that the Employee
     may receive from any other source.

Section 8: Other Terminations Under This Part

If  termination  of  employment,  actual or  constructive,  is not  described in
Section 7, then the Employee is entitled only to the compensation,  benefits and
reimbursements  payable under the terms of Sections 3, 4 and 5 of this Agreement
for the period  preceding the effective  date of the  termination  including any
disability or death benefits to which Employee (or his estate or beneficiary(s))
may be  entitled  as a result of  termination  of his  employment  on account of
Disability or death. The payments under this Agreement shall fully discharge all
responsibilities  of the  Corporation  to the Employee upon  termination  of the
Employee's  employment.  This  Section 8  applies,  without  limitation,  to any
termination initiated by the Employee (except an Employee-initiated  termination
that is described in Paragraph 2 of Section  7(a)),  termination  of  employment
caused by the Employee's  death or  Disability,  termination of the Employee for
Cause, and any constructive termination (not described in Section 7).

Notwithstanding  anything in this Section 8 to the contrary, if Employee remains
an employee of the Corporation for a minimum period of twelve months  commencing
after  the  date  hereof,  then  Employee  will  have the  right to  voluntarily
terminate his employment with the Corporation anytime thereafter and receive (1)
six months  salary and fifty  percent  (50%) of the greater of the prior  year's
incentive bonus or his annual  incentive bonus earned on a quarterly basis as of
the date of  termination,  assuming the Employee was employed on the last day of
the  quarter  in which  the  termination  occurred,  and (2) six  months of life
insurance  and  health  care  coverage  as  described  in  Section  7(c)  of the
Agreement.

Section 9: Definition of Change in Control

For all purposes under this Agreement,  "Change in Control" shall mean a "Change
in Control" of the Corporation,  as defined in the Netcom On-Line  Communication
Services, Inc. 1993 Stock Option Plan as in effect on the date this Agreement is
executed,  provided,  however,  that neither the January, 5, 1999 Asset Purchase
Agreement  between Netcom On-Line  Communication  Services,  Inc. and MindSpring
Enterprises  Inc.  regarding the sale of certain  assets or the results  arising
directly and immediately therefrom shall be considered a Change in Control.

                                       7


THIRD PART:  PARACHUTE PAYMENTS

Section 10:  Gross-Up Payment:

In the event it is determined that any payment or distribution of any type to or
for the benefit of the Employee, pursuant to this Agreement or otherwise, by the
Corporation,  any Person who  acquires  ownership  or  effective  control of the
Corporation,  or  ownership  of a  substantial  portion  of  the  assets  of the
Corporation  (within the meaning of section 260G of the Code and the regulations
thereunder)  or any  affiliate  of such Person (the "Total  Payments")  would be
subject to the exise tax imposed by section  4999 of the Code or any interest or
penalties  with respect to such excise tax (such excise tax,  together  with any
such interest and penalties,  are collectively referred to as the "Excise Tax"),
then the  Employee  shall be  entitled  to  receive  an  additional  payment  (a
"Gross-Up Payment") in an amount such that, after payment by the Employee of all
taxes (including any interest or penalties  imposed with respect to such taxes),
including  any Excise Tax,  imposed  upon the  Gross-Up  Payment,  the  Employee
retains an amount of the Gross-Up  Payment  equal to the Excise Tax imposed upon
the Total Payments.

Section 11:  Determination by Accountant

All  mathematical  determinations  and  determinations  as to whether any of the
Total Payments are "parachute  payments"  (within the meaning of section 280G of
the Code), in each case which  determinations are required to be made under this
Section 11, including whether a Gross-Up Payment is required, the amount of such
Gross-Up Payment,  and amounts relevant to the last sentence of this Section 11,
shall be made by an  independent  accounting  firm selected by the Employee from
among the largest six  accounting  firms in the United  States (the  "Accounting
Firm"). The Accounting Firm shall provide to the Corporation and to the Employee
its  determination  (the  "Determination"),  together with  detailed  supporting
calculations regarding the amount of any Gross-Up Payment and any other relevant
matter,  within ten days after  termination  of the  Employee's  employment,  if
applicable,  or at such earlier time  following  termination of employment as is
requested by the Employee (if the Employee  reasonably  believes that any of the
Total  Payments  may be subject  to the  Excise  Tax).  If the  Accounting  Firm
determines  that no Excise Tax is payable by the Employee,  it shall furnish the
Employee with a written  statement that such  Accounting Firm has concluded that
no Excise Tax is payable  (including the reasons therefor) and that the Employee
has substantial authority not to report any Excise Tax on the Employee's federal
income tax return.  If a Gross-Up Payment is determined to be payable,  it shall
be paid to the Employee within ten days after the  Determination is delivered to
the Corporation or the Employee.  Any determination by the Accounting Firm shall
be binding upon the Corporation and the Employee, absent manifest error.

As a result of uncertainty in the application of section 4999 of the Code at the
time of the  initial  determination  by the  Accounting  Firm  hereunder,  it is
possible that Gross-Up  Payments not made by the  Corporation and members of the
Corporation  should have been made  ("Underpayment"),  or that Gross-Up Payments
will have been made by the  Corporation  and  members  of the  Corporation  that
should not have been made ("Overpayments"). In either such event, the Accounting
Firm shall  determine the amount of the  Underpayment  or  Overpayment  that has
occurred. In the case of an Underpayment, the Corporation promptly shall pay, or
cause to be paid, the amount of such  Underpayment  to or for the benefit of the
Employee.  In the case of an  Overpayment,  the Employee shall, at the direction
and  expense of the  Corporation,  take such steps as are  reasonably  necessary
(including  the filing of returns  and claims  for  refund),  follow  reasonable
instructions from, and procedures established by the Corporation,  and otherwise
reasonably cooperate with the Corporation to correct such Overpayment; provided,


                                       8


however,  that (1) Employee shall not in any event be obligated to return to the
Corporation an amount greater than the net after-tax  portion of the Overpayment
that he has  retained  or  recovered  as a  refund  from the  applicable  taxing
authorities and (2) this provision  shall be interpreted in a manner  consistent
with the  intent of  Section  13,  which is to make the  Employee  whole,  on an
after-tax  basis,  from the  application of the Excise Tax, it being  understood
that the correction of an Overpayment may result in the Employee repaying to the
Corporation an amount that is less than the Overpayment.


                                       9



FOURTH PART:  TRADE SECRETS, SUCCESSORS, MISCELLANEOUS  
              PROVISIONS, SIGNATURE PAGE

Section 12:  Confidential Information

(a)  Acknowledgment.  The  Corporation  and the  Employee  acknowledge  that the
     services to be performed by the Employee  under this  Agreement  are unique
     and extraordinary and that, as a result of the Employee's  employment,  the
     Employee  will be in a  relationship  of  confidence  and  trust  with  the
     Corporation and will come into possession of "Confidential Information" (1)
     owned  or  controlled  by the  Corporation,  (2) in the  possession  of the
     Corporation and belonging to third parties,  or (3) conceived,  originated,
     discovered  or developed,  in whole or in part,  by the  Employee.  As used
     herein   "Confidential   Information   includes  trade  secrets  and  other
     confidential  or proprietary  business,  technical,  personnel or financial
     information,  whether  or not the  Employee's  work  product,  in  written,
     graphic,  oral or other  tangible or  intangible  forms,  including but not
     limited to  specifications,  samples,  records,  data,  computer  programs,
     drawings,  diagrams,  models,  customer  names,  ID's or  email  addresses,
     business or marketing plans,  studies,  analyses,  projections and reports,
     communications  by or to attorneys  (including  attorney-client  privileged
     communications),  memos and other materials  prepared by attorneys or under
     their direction (including attorney work product), and software systems and
     processes.  Any  information  that is not readily  available  to the public
     shall be considered to be a trade secret and  confidential and proprietary,
     even if it is not  specifically  marked  as such,  unless  the  Corporation
     advises the Employee otherwise in writing.

(b)  Nondisclosure.  The Employee agrees that the Employee will not, without the
     prior written  consent of the  Corporation,  directly or indirectly  use or
     disclose  Confidential  Information  to any  person,  during  or after  the
     Employee's employment, except as may be necessary in the ordinary course of
     performing the Employee's  duties under this  Agreement.  The Employee will
     keep the Confidential  Information in strictest  confidence and trust. This
     Section 15 shall apply indefinitely, both during and after the term of this
     Agreement.

(c)  Surrender Upon  Termination.  The Employee  agrees that in the event of the
     termination of the Employee's  employment for any reason, the Employee will
     immediately  deliver  to the  Corporation  all  property  belonging  to the
     Corporation, including all documents and materials of any nature pertaining
     to the  Employee's  work with the  Corporation,  and will not take with the
     Employee any documents or materials of any description, or any reproduction
     thereof of any  description,  containing or pertaining to any  Confidential
     Information.  It is understood that the Employee is free to use information
     that  is in the  public  domain  (not  as a  result  of a  breach  of  this
     Agreement).

Section 13:  Successors

(a)  Corporation's  Successors.  The  Corporation  shall  require any  successor
     (whether  direct or  indirect  and  whether  by  purchase,  lease,  merger,
     consolidation, liquidation or otherwise) to all or substantially all of the
     Corporation's business and/or assets, by an agreement in substance and form
     satisfactory  to the  Employee,  to  assume  this  Agreement  and to  agree
     expressly  to perform  this  Agreement  in the same  manner and to the same
     extent as the Corporation would be required to perform it in the absence of
     a succession.  The Corporation's  failure to obtain such agreement prior to


                                       10


     the  effectiveness  of a succession shall be a breach of this Agreement and
     shall entitle the Employee to all of the compensation and benefits to which
     the Employee  would have been  entitled  hereunder if the  Corporation  had
     involuntarily   terminated  the  Employee's  employment  without  Cause  or
     Disability,  on the date when such succession  becomes  effective.  For all
     purposes under this  Agreement,  the term  "Corporation"  shall include any
     successor to the  Corporation's  business  and/or  assets that executes and
     delivers the assumption  agreement described in this Subsection (a) or that
     becomes bound by this Agreement by operation of law.

(b)  Employee's  Successors.  This  Agreement  and all  rights  of the  Employee
     hereunder  shall  inure to the  benefit  of,  and be  enforceable  by,  the
     Employee's personal or legal  representatives,  executors,  administrators,
     successors, heirs, distributees, devisees and legatees.

Section 14:  Miscellaneous Provisions

(a)  Waiver.  No  provision  of this  Agreement  shall be  modified,  waived  or
     discharged  unless the  modification,  waiver or  discharge is agreed to in
     writing  and signed by the  Employee  and by an  authorized  officer of the
     Corporation  (other than the  Employee).  No waiver by either  party of any
     breach of, or of  compliance  with,  any  condition  or  provision  of this
     Agreement  by the other  party  shall be  considered  a waiver of any other
     condition  or  provision  or of the same  condition or provision at another
     time.

(b)  Whole Agreement. No agreements,  representations or understandings (whether
     oral or written and whether  express or implied) that are not expressly set
     forth in this Agreement have been made or entered into by either party with
     respect to the subject  matter  hereof.  In addition,  the Employee  hereby
     acknowledges and agrees that this Agreement  supersedes in its entirety any
     employment  agreement  between the Employee and the  Corporation  in effect
     immediately  prior  to the  effective  date  of this  Agreement.  As of the
     effective date of this Agreement, such employment agreement shall terminate
     without any further  obligation by either party  thereto,  and the Employee
     hereby relinquishes any further rights that the Employee may have had under
     such prior employment agreement.

(c)  Notice. Notices and all other communications contemplated by this Agreement
     shall be in  writing  and shall be deemed  to have  been  duly  given  when
     personally  delivered or when mailed by U.S.  registered or certified mail,
     return receipt requested and postage prepaid.  In the case of the Employee,
     mailed  notices shall be addressed to the Employee at the home address that
     the Employee most recently  communicated to the Corporation in writing.  In
     the case of the  Corporation,  mailed  notices  shall be  addressed  to its
     corporate headquarters,  and all notices shall be directed to the attention
     of its Chief Executive Officer.

(d)  No Setoff. There shall be no right of setoff or counterclaim,  with respect
     to any claim,  debt or obligation,  against  payments to the Employee under
     this Agreement.

(e)  Choice Of Law. The validity,  interpretation,  construction and performance
     of this Agreement shall be governed by the laws of the State of California,
     irrespective of California's choice-of-law principles.

                                       11


(f)  Severability.  The  invalidity  or  unenforceability  of any  provision  or
     provisions   of  this   Agreement   shall  not  affect  the   validity   or
     enforceability  of any other provision  hereof,  which shall remain in full
     force and effect.

(g)  Arbitration.  Except  as  otherwise  provided  in  Section  14  and  in the
     enforcement  of Section 15, any dispute or  controversy  arising out of the
     Employee's  employment  or the  termination  thereof,  including,  but  not
     limited to, any claim of  discrimination  under state or federal law, shall
     be  settled  exclusively  by  arbitration  in  San  Jose,  California,   in
     accordance with the rules of the American  Arbitration  Association then in
     effect.  Judgment  may be  entered on the  arbitrator's  award in any court
     having jurisdiction.

(h)  No Assignment of Benefits. The rights of any person to payments or benefits
     under this  Agreement  shall not be made  subject to option or  assignment,
     either by  voluntary  or  involuntary  assignment  or by  operation of law,
     including (without limitation) bankruptcy, garnishment, attachment or other
     creditor's  process,  and any action in  violation of this  Subsection  (h)
     shall be void.

(i)  Employment  at  Will;  Limitation  of  Remedies.  The  Corporation  and the
     Employee acknowledge that the Employee's  employment is at will, as defined
     under  applicable  law. If the  Employee's  employment  terminates  for any
     reason,  the  Employee  shall not be  entitled to any  payments,  benefits,
     damages, awards or compensation other than as provided by this Agreement.

(j)  Employment  Taxes.  All payments made pursuant to this  Agreement  shall be
     subject to withholding of applicable taxes.

(k)  Benefit Coverage  Non-Additive.  In the event that the Employee is entitled
     to life  insurance and health plan  coverage  under more than one provision
     hereunder,  only one  provision  shall  apply,  and  neither the periods of
     coverage nor the amounts of benefits shall be additive.

Section 15: Effectiveness.

Notwithstanding anything in this Agreement to the contrary, this Agreement shall
only be effective upon the closing of the MindSpring Agreement. In the event the
MindSpring  Agreement does not close, then this Agreement shall be null and void
and the  First  Employment  Agreement  shall  remain in full  force  and  effect
according to its terms and conditions.

Section 16 : Release.

Each party does hereby  release,  acquit and forever  discharge the other party,
its related entities, parents,  subsidiaries,  agents, employees,  predecessors,
successors  and assigns  and any other  person or entity of and from any and all
past, present or future claims for payment,  claims or obligations of any nature
whatsoever,  whether compensatory or punitive or any other nature,  arising from
or in connection  with the First  Employment  Agreement.  This  Agreement  shall
replace the First Employment  Agreement and the First Employment Agreement shall
be void and of no effect.


IN WITNESS WHEREOF, each of the parties has executed this Agreement, in the case
of the Corporation by its duly authorized  officer, as of the day and year first


                                       12


above  written.  Employee has consulted (or has had the  opportunity to consult)
with his own counsel prior to execution of this Agreement.

AGREED AND ACCEPTED

Michael D. Kallet




/s/ Michael D. Kallet
- ---------------------------


ICG PST, Inc.



By    Mike D. Kallet
      ----------------------------
Title President
      ---------------------------



                                      Read, Acknowledged and Agreed to:



                                      ICG Communications, Inc.



                                      By /s/ Harry R. Herbst
                                         -----------------------------

                                      Title EVP, CFO
                                            --------------------------