<PAGE>
                                        
                             THIRD AMENDMENT TO LEASE

      THIS THIRD AMENDMENT TO LEASE ("Third Amendment") is made and entered 
into as of August 11, 1998, by and between WHMNY REAL ESTATE LIMITED 
PARTNERSHIP, a Delaware limited partnership ("Landlord"), and EARTHLINK 
NETWORK, INC., a Delaware corporation ("Tenant").

                                    RECITALS

     A.   ORIGINAL LEASE.  Pursuant to that certain Office Lease dated 
September 26, 1996 (the "Original Lease"), Landlord's predecessor in 
interest, The Mutual Life Insurance Company of New York ("MONY"), leased to 
Tenant certain premises in Suite 100 consisting of the first floor (the 
"Original Premises") of the building located at 2947 Bradley Street, 
Pasadena, California, 91107 (the "Building").

     B.   FIRST AMENDMENT.  The Original Lease was amended by that certain 
First Amendment to Lease (the "First Amendment") dated February 1997, and by 
the following letter agreements, each by and between MONY and Tenant:  that 
certain letter agreement dated October 8, 1996 (regarding the letter of 
credit); that certain letter agreement dated October 10, 1996 (regarding 
submetering of utilities); that certain letter agreement dated November 18, 
1996 (regarding modification to parabolic light fixtures); and that certain 
letter agreement dated February 24, 1997 (regarding payment for submeters) 
(collectively, the "Letter Agreements").

     C.   SECOND AMENDMENT.  The Original Lease was further amended to 
confirm the size of the Original Premises by that certain Second Amendment 
to Lease (the "Second Amendment") dated February 1997, by and between MONY 
and Tenant.

     D.   EXISTING LEASE.  The Original Lease, as amended by the First 
Amendment, the Letter Agreements, and the Second Amendment, is referred to 
herein as the "Existing Lease."

     E.   LEASE.  The Existing Lease, as amended by this Third Amendment, is 
referred to herein as the Lease.

     F.   PURPOSE.  Landlord and Tenant desire to further amend the Existing 
Lease as set forth herein.
                                       
                                   AGREEMENT

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

     1.   PREMISES.  The description of the Premises set forth in the 
Existing Lease is hereby amended by adding the following:

          Landlord hereby leases to Tenant and Tenant hereby leases
          from Landlord the lobby area on the first floor and the
          entire second floor of the Building (the "First Additional
          Premises"), as shown on the floor plan attached hereto as
          Exhibit "A."   Unless otherwise expressly provided to the
          contrary herein, on and after the First Additional Premises
          Commencement Date (defined below) the term "Premises" as
          used in this Lease shall consist of the Existing Premises 
          (the entire first floor) and the First Additional Premises 
          (the first floor lobby and the entire second floor), for a 
          total of approximately 110,497 rentable square feet, and 
          shall be commonly referred to as Suite 100.  Except as
          otherwise provided in this Third Amendment, the First
          Additional Premises shall be leased by Tenant on the same
          terms and conditions as are applicable from time to time to
          the Existing Premises.

<PAGE>

     2.   TERM.  The description of the term set forth in the Existing Lease 
is hereby amended by adding the following:

          The term of this Lease with respect to the First Additional
          Premises shall commence on October 1, 1998 (the "First
          Additional Premises Commencement Date"), shall run
          concurrently with the remaining term of the Existing Lease,
          and shall terminate on February 13, 2007.  Notwithstanding
          the foregoing to the contrary, upon the full execution of
          this Third Amendment by Landlord and Tenant, and until the
          First Additional Premises Commencement Date, Tenant shall
          have the right to occupy the First Additional Premises,
          subject to all of the provisions of this Lease excepting
          only those requiring the payment of Rent respecting the
          First Additional Premises.

     3.   MONTHLY RENTAL.  Section IVA of the Original Lease, Exhibit D 
attached to the Original Lease, and paragraph 3c of the Second Amendment are 
hereby amended by adding the following:

          Tenant agrees to pay to Landlord, as Monthly Rental for the
          Existing Premises and the First Additional Premises, the
          amounts set forth below per month for the time periods set
          forth below payable on the first day of each calendar month
          without offset or deduction during the term of this Lease.

<TABLE>
<CAPTION>

                      EFFECTIVE DATES         MONTHLY RENTAL
                      ---------------         --------------
                      <S>                      <C>
                      10/01/1998-09/30/1999    $ 92,071.00
                      10/01/1999-01/31/2002    $147,081.00
                      02/01/2002-02/28/2002    $153,294.00
                      03/01/2002-12/31/2003    $158,046.00
                      01/01/2004-01/31/2007    $167,307.00
                      02/01/2007-02/13/2007    $ 72,499.70
</TABLE>

     4.   COMMON OPERATING COSTS.  Section IQ of the Original Lease, and 
paragraph 3b of the Second Amendment are hereby amended by adding the 
following:

          On and after the First Additional Premises Commencement
          Date, Tenant's Proportionate Share of Common Operating Costs
          shall be 100%.

     5.   PARKING.  As of the First Additional Premises Commencement Date, 
Tenant shall have the exclusive use of the entire Building, including its 
parking lot, and Tenant shall have no obligation to pay rent for the use of 
the spaces in such lot.

     6.   SECURITY DEPOSIT.  Section IL of the Original Lease, and Section 
XXXV.D of the Addendum attached to the Original Lease, are hereby amended by 
adding the following:

          On or before the First Additional Premises Commencement
          Date, Tenant shall deliver a new Letter of Credit from no more
          than two (2) banks in the aggregate amount of $1,000,000.00 as
          security for Tenant's full and faithful performance of its
          obligations and payments due under this Lease (the "New
          Letter of Credit").  Once the New Letter of Credit is
          delivered to Landlord, the existing Letter of Credit in
          effect at the time of execution of this Third Amendment (the
          "Existing Letter of Credit") shall be cancelled and shall be of 
          no further force or effect.  Upon execution of this Third Amendment
          by Landlord and Tenant, Landlord shall deliver the Existing Letter
          of Credit to the bank that issued same, to be held in trust by such
          bank

                                       2

<PAGE>

          pending the issuance of the New Letter of Credit and the subsequent
          cancellation of the Existing Letter of Credit.  All terms of 
          Section XXXV.D of the Addendum to the Original Lease respecting 
          the Existing Letter of Credit shall apply to the New Letter of 
          Credit, with the following exceptions:  the Anniversary Dates 
          shall be measured from the First Additional Premises Commencement 
          Date, and the aggregate amount of the New Letter of Credit shall 
          be reduced by $120,000.00 yearly on the Anniversary Dates, as set 
          forth below:

<TABLE>
<CAPTION>

                                               AMOUNT OF RENEWED
                   ANNIVERSARY DATES           NEW LETTER OF CREDIT
                   -----------------           --------------------
                   <S>                         <C>
                   10/01/1998                  $1,000,000.00
                   10/01/1999                  $  880,000.00
                   10/01/2000                  $  760,000.00
                   10/01/2001                  $  640,000.00
                   10/01/2002                  $  520,000.00
                   10/01/2003                  $  400,000.00
                   10/01/2004                  $  280,000.00
                   10/01/2005                  $  160,000.00
                   10/01/2006-02/13/2007       $   40,000.00

</TABLE>

     7.   TENANT IMPROVEMENT ALLOWANCE.  Landlord shall provide Tenant with a 
Tenant Improvement Allowance in the amount of $1,231,900.00 (the "Tenant 
Improvement Allowance") to be applied towards the cost of the work to be 
performed within the Premises by Tenant (the "Tenant Improvements"), in 
accordance with the Work Letter attached hereto as Exhibit "B." Landlord and 
Tenant acknowledge and agree that on or before March 31, 2000, the entire 
Tenant Improvement Allowance must be used for the Tenant Improvement Costs 
(as defined in the Work Letter), and any unused amount after such date shall 
be retained by Landlord.

     8.   EXPANSION OPTIONS.  Sections XXXV.A(1) and XXXV.A(2) of the Addendum 
to the Original Lease are hereby deleted in their entirety and Landlord and 
Tenant acknowledge that Tenant has no right to further expand in the Building.

     9.   BROKERS.  Neither Landlord nor Tenant has dealt with any broker or 
agent in connection with the negotiation or execution of this Third 
Amendment, other than Insignia/ESG and Ramsey-Shilling Commercial Real Estate 
Services, Inc. ("RSCO").  Landlord shall pay Insignia/ESG a commission in the 
amount of three percent (3%) for months 1 through 60, and one and one-half 
percent (1-1/2%) for months 61 through 101, in accordance with a separate 
listing agreement, and shall pay RSCO a commission in the amount of four 
percent (4%) for months 1 through 60, and two percent (2%) for months 61 
through 101, in accordance with a separate commission agreement originally by 
and between MONY and RSCO, and assumed by Landlord. Tenant and Landlord shall 
each indemnify the other against all costs, expenses, attorney fees, and 
other liability for commissions or other compensation claimed by any broker 
or agent claiming the same by, through, or under the indemnifying party.

     10.  FULL FORCE AND EFFECT.  Except as expressly amended by this Third 
Amendment, the Existing Lease shall remain in full force and effect for the 
entire remaining term and any extensions thereof.

                                       3

<PAGE>

     IN WITNESS WHEREOF, the parties hereto have executed this Third 
Amendment effective as of the date first written above.

LANDLORD:                     WHMNY REAL ESTATE LIMITED
                              PARTNERSHIP, a Delaware limited partnership
                              
                              By:  WHMNY GEN-PAR, INC., a Delaware
                                   corporation, General Partner
     
     
                              By:                                
                                  ------------------------------------
                                  Name:     Nancy M. Haag
                                  Title:    Assistant Vice President

TENANT:                       EARTHLINK NETWORKS, INC.
                              a Delaware corporation
                              
                              By:                                
                                  -------------------------------------
                              Name:         
                                      ---------------------------------
                              Title:       
                                      ---------------------------------


                              By:                                
                                  -------------------------------------
                              Name:         
                                      ---------------------------------
                              Title:       
                                      ---------------------------------



                                       4

<PAGE>


                                  EXHIBIT "A"
                                          
                   DESCRIPTION OF FIRST ADDITIONAL PREMISES



                             [DIAGRAM OF 2ND FLOOR]
                                          
                                          

 [LOGO] INSIGNIA                                 2ND FLOOR
 COMMERICIAL GROUP, INC.
 FOR LEASING INFORMATION               2947 BRADLEY STREET, PASADENA, CA
 CALL CONAN COTRELL AT (310)235-3037

<PAGE>

                                  EXHIBIT "B"
                                          
                                  WORK LETTER
                         (TENANT IMPROVEMENT ALLOWANCE)

     This Work Letter is attached to and made a part of that certain Third 
Amendment to Lease dated as of August 11, 1998 ("Third Amendment") by and 
between Landlord and Tenant for the First Additional Premises consisting of 
the lobby area on the first floor and the second floor of the Building 
located at 2947 Bradley Street, Pasadena, California, 91107.

1.   APPLICATION OF EXHIBIT.  Capitalized terms used and not otherwise 
defined herein shall have the same definitions as set forth in the Existing 
Lease.  The provisions of this Work Letter shall apply to the planning and 
completion of leasehold improvements to be constructed by Tenant (the "Tenant 
Improvements") for the build-out of the First Additional Premises, as more 
fully set forth herein.

2.   LANDLORD AND TENANT PRE-CONSTRUCTION OBLIGATIONS.

     (a)  PRELIMINARY PLANS.  Tenant shall cause Wirt Design Group ("Tenant's 
Architect") to prepare preliminary space plans for the Tenant Improvements 
(the "Preliminary Plans"), which shall include, without limitation, sketches 
and/or drawings showing locations of doors, partitioning, electrical 
fixtures, outlets and switches, plumbing fixtures, floor loads and other 
requirements, and a list of all specialized installations and improvements 
and upgrade specifications determined by Tenant as required for its use of 
the First Additional Premises. It is contemplated that the Tenant 
Improvements will be completed in several phases as such space is needed by 
Tenant, and that separate Preliminary Plans and Working Drawings will be 
prepared for each phase of such work.  The Preliminary Plans and Working 
Drawings shall be reviewed by Landlord's Architect and the cost thereof shall 
be paid by Landlord and included within the Tenant Improvement Allowance; 
provided that the total sum for such review that will be deducted from the 
Tenant Improvement Allowance shall in no event exceed $900.00, determined as 
follows: $400.00 for architectural review, and $500.00 for mechanical, 
electrical, plumbing and structural review.  Landlord and Landlord's 
Architect shall be entitled, in all respects, to rely upon all information 
supplied by Tenant regarding the Tenant Improvements.  The costs associated 
with Tenant's Architect's preparation of the Preliminary Plans shall be borne 
by Tenant and paid as set forth in Sections 5 and 6 of this Work Letter.

     (b)  APPROVAL OF PRELIMINARY PLANS.  Tenant or Tenant's Architect shall 
submit the Preliminary Plans to Landlord for Landlord's review and approval, 
which approval shall not be unreasonably withheld, delayed or conditioned. 
Landlord shall notify Tenant within five (5) business days after delivery 
thereof if the Preliminary Plans are approved.  If Landlord withholds 
approval, Landlord shall so notify Tenant and specify the reasons for 
withholding such approval.  If the Preliminary Plans are not approved, then 
within five (5) days after receipt of such notice, Tenant's Architect shall 
make all necessary revisions to the Preliminary Plans and submit two (2) 
copies thereof to Landlord for its final review and approval, which approval 
shall not be unreasonably withheld, delayed or conditioned, and shall be 
given within five (5) business days thereafter.  If no response is given by 
Landlord within the five (5) business day period, approval shall be deemed.

     (c)  WORKING DRAWINGS.  Within thirty (30) days following the 
Preliminary Plans Approval Date, Tenant's Architect shall prepare working 
drawings (the "Working Drawings") for the Tenant Improvements based upon the 
approved Preliminary Plans.  The Working Drawings shall include 
architectural, necessary mechanical and electrical construction drawings for 
the Tenant Improvements based on the Preliminary Plans.  Notwithstanding the 
Preliminary Plans, in all cases the Working Drawings (i) shall be subject to 
Landlord's final approval, which approval shall not be unreasonably withheld, 
delayed, or conditioned, (ii) shall not be in conflict with building codes 
for the City of Pasadena ("City") or County of Los Angeles ("County") or with 
insurance requirements for a fire resistive building, and (iii) shall be in a 
form satisfactory to appropriate governmental 

                                      B-1

<PAGE>

authorities responsible for issuing permits and licenses required for 
construction.  The costs associated with preparation of the Working Drawings 
shall be borne by Tenant and paid as set forth in Sections 5 and 6 of this 
Work Letter.

     (d)  APPROVAL OF WORKING DRAWINGS.  Tenant or Tenant's Architect shall 
submit the Working Drawings to Landlord for its review and approval, which 
shall not be unreasonably withheld.  Landlord shall notify Tenant within five 
(5) business days after delivery thereof if the Working Drawings are 
approved.  If Landlord withholds approval, Landlord shall so notify Tenant 
and specify the reasons for withholding such approval.  If the Working 
Drawings are not approved, within five (5) days after receipt of Landlord's 
notice, Tenant's Architect shall make all necessary revisions to the Working 
Drawings and submit two (2) copies thereof to Landlord for its final review 
and approval, which approval shall not be unreasonably withheld, delayed or 
conditioned and shall be given within five (5) days thereafter.  If no 
response is given by Landlord within the five (5) day period, approval shall 
be deemed.  Concurrently with the above review and approval process, Tenant 
may submit all plans and specifications to City and other applicable 
governmental agencies in an attempt to expedite City approval and issuance of 
all necessary permits and licenses to construct the Tenant Improvements as 
shown on the Working Drawings.  Any changes which are required by City or 
other governmental agencies shall be immediately submitted to Landlord for 
Landlord's review and reasonable approval, and to Tenant for Tenant's review 
and approval.

     (e)  SCHEDULE OF CRITICAL DATES.  Set forth on Exhibit "B-1" attached 
hereto below is a schedule of certain probable dates relating to Landlord's 
and Tenant's respective obligations for the design and construction of the 
Tenant Improvements.  Such dates and the respective obligations of Landlord 
and Tenant are more fully described elsewhere in this Work Letter.  The 
purpose of the schedule is to provide a reference for Landlord and Tenant so 
as to make certain the Final Approval Date occurs for each particular phase 
of the work as set forth herein.  Following the Final Approval Date for each 
phase Tenant shall commence construction of the Tenant Improvements for that 
particular phase of the work as set forth in Section 4 below.

3.  BUILDING PERMIT.  After the Final Approval Date for each phase has 
occurred, Tenant shall, if Tenant has not already done so, submit the Working 
Drawings to the appropriate governmental body or bodies for final plan 
checking and a building permit.  Tenant, with Landlord's cooperation, shall 
cause to be made any change in the Working Drawings necessary to obtain the 
building permit; provided, however, after the Final Approval Date, no changes 
shall be made to the Working Drawings without the prior written approval of 
both Landlord and Tenant, and then only after agreement by Tenant to pay any 
excess costs resulting from such changes. Tenant may direct Landlord to pay 
such excess costs out of the Tenant Improvement Allowance to the extent 
available.

4.  CONSTRUCTION OF TENANT IMPROVEMENTS.

     (a)  CONSTRUCTION.  After the Final Approval Date has occurred and a 
building permit for the work has been issued, Tenant shall select a licensed 
general contractor ("Contractor") subject to Landlord's approval, which 
approval shall not be unreasonably withheld, delayed or conditioned and 
Tenant shall notify Landlord of same upon its selection.  Tenant shall enter 
into a construction contract ("Construction Contract") with the Contractor, 
who shall cause the construction of the Tenant Improvements to be carried out 
in substantial conformance with the Working Drawings in a good and 
workmanlike manner using first-class materials.  The Contractor and Tenant's 
Agents (defined in Section 5(c) below) shall abide by all reasonable rules 
and regulations of Landlord (copies of which have been given to Tenant) with 
respect to the construction of the Tenant Improvements. The costs associated 
with the construction of the Tenant Improvements shall be borne by Tenant and 
paid as set forth in Sections 5 and 6 of this Work Letter.  Tenant shall see 
that the construction complies with all applicable building, fire, health, 
and sanitary codes and regulations, the satisfaction of which shall be 
evidenced by a certificate of occupancy for the Premises.

     (b)  NOTICE OF COMPLETION.  Within ten (10) business days after the 
issuance of the permanent or temporary certificate of occupancy for the 
Tenant Improvements, Tenant shall cause 

                                       B-2

<PAGE>

a Notice of Completion to be recorded in the office of the Recorder of the 
County of Los Angeles in accordance with Section 3093 of the Civil Code of 
the State of California or any successor statute, and shall furnish a copy 
thereof to Landlord upon such recordation.

5.   TENANT IMPROVEMENT ALLOWANCE.

     (a)  TENANT IMPROVEMENT ALLOWANCE.  Landlord shall provide Tenant with 
an allowance in the amount of $1,231,900.00 ("Tenant Improvement Allowance") 
towards the cost of the design, purchase and construction of the Tenant 
Improvements, including without limitation design, engineering and consulting 
fees (collectively, the "Tenant Improvement Costs").  The Tenant Improvement 
Allowance shall be used for payment of the following Tenant Improvement Costs:

          (i)   Preparation by Tenant's Architect of all necessary documents 
in connection with the Tenant Improvements, including without limitation the 
Preliminary Plans and the Working Drawings as provided in Section 2 of this 
Work Letter, and all fees charged by City (including without limitation fees 
for building permits and plan checks) in connection with construction of the 
Tenant Improvements in the First Additional Premises;

          (ii)  Construction work for completion of the Tenant Improvements 
as reflected in the Construction Contract including, without limitation, 
testing and inspection costs, freight elevator charges, utility usage, and 
trash removal costs;

          (iii) All contractor's charges, general conditions, reasonable 
performance bond premiums and construction fees;

          (iv)  The cost of any changes in the Base Building when such 
changes are required by the Construction Drawings (including all direct 
architectural and/or engineering fees and expenses incurred in connection 
therewith);

          (v)   The cost of any changes to the Construction Drawings or 
Tenant Improvements required by applicable Law;

          (vi)  Any other expenses incurred by Tenant in making the Premises 
ready for its occupancy, including without limitation carpeting, wiring, 
communication systems and furnishings; and

     (b)  DISBURSEMENT OF TENANT IMPROVEMENT ALLOWANCE AND EXCESS COSTS.  
During the construction of the Tenant Improvements, Landlord shall make 
monthly disbursements of the Tenant Improvement Allowance for Tenant 
Improvement Costs for the benefit of Tenant and shall authorize the release 
of monies for the benefit of Tenant as set forth below. Landlord and Tenant 
acknowledge and agree that on or before March 31, 2000, the entire Tenant 
Improvement Allowance must be disbursed for the payment of Tenant Improvement 
Costs and any Tenant Improvement Allowance remaining on April 1, 2000 shall 
be retained by Landlord.

          (i)   MONTHLY DISBURSEMENTS.  On or before the tenth (10th) day of 
each calendar month, as determined by Landlord, during the construction of 
the Tenant Improvements, Tenant shall deliver to Landlord as appropriate:  
(i) a request for payment of the "Contractor," as that term is defined in 
Section 4 of this Work Letter, approved by Tenant, in a form reasonably 
approved by Landlord, showing the schedule, by trade, of percentage of 
completion of the Tenant Improvements in the Premises, detailing the portion 
of the work completed and the portion not completed; (ii) invoices from all 
of "Tenant's Agents" (as defined in Section 5(c) below), for labor rendered 
and materials delivered to the Premises for the applicable payment period; 
(iii) executed conditional mechanic's lien releases from all of Tenant's 
Agents which shall comply with the appropriate provisions, as reasonably 
determined by Landlord, of California Civil Code Section 3262(d); and 

                                     B-3

<PAGE>

(iv) all other information reasonably requested by Landlord.  Tenant's 
request for payment shall be deemed Tenant's acceptance and approval of the 
work furnished and/or the materials supplied as set forth in Tenant's payment 
request.  Thereafter, Landlord shall deliver a check to Tenant made jointly 
payable to Contractor and Tenant in payment of the amounts so requested by 
Tenant, as set forth in this Section 5(b), above, less a ten percent (10%) 
retention (the aggregate amount of such retentions to be known as the "Final 
Retention"), provided that Landlord does not reasonably dispute any request 
for payment based on non-compliance of any work with the approved Working 
Drawings, or due to any substandard work or for any other reason.  Landlord's 
payment of such amounts shall not be deemed Landlord's approval or acceptance 
of the work furnished or materials supplied as set forth in Tenant's payment 
request.

          (ii)  FINAL RETENTION.  Subject to the provisions of this Work 
Letter, a check for the Final Retention payable jointly to Tenant and 
Contractor shall be delivered by Landlord to Tenant following the completion 
of construction of the Premises, provided that (i) Tenant delivers to 
Landlord properly executed mechanics lien releases in compliance with both 
California Civil Code Section 3262(d)(2) and either Section 3262(d)(3) or 
Section 3262(d)(4), (ii) Landlord has reasonably determined that no 
substandard work exists which adversely affects the mechanical, electrical, 
plumbing, heating, ventilating and air conditioning, life-safety or other 
systems of the Building, the curtain wall of the Building, the structure or 
exterior appearance of the Building, or any other tenant's use of such other 
tenant's leased premises in the Building, and (iii) Tenant's Architect 
delivers to Landlord a certificate, in a form reasonably acceptable to 
Landlord, certifying that the construction of the Tenant Improvements in the 
Premises has been substantially completed.

     (c)  TENANT'S AGENTS.  All subcontractors, laborers, materialmen and 
suppliers used by Tenant (such subcontractors, laborers, materialmen and 
suppliers and the Contractor to be known collectively as "Tenant's Agents") 
must be approved in writing by Landlord, which approval shall not be 
unreasonably withheld, delayed or conditioned.

6.   COSTS IN EXCESS OF TENANT IMPROVEMENT ALLOWANCE AT TENANT'S EXPENSE. 
Tenant shall pay the excess of the Tenant Improvement Costs over the amount 
of the Tenant Improvement Allowance available to defray such costs.  
Concurrent with the final plan checking referred to in Section 3 of this Work 
Letter, Tenant shall prepare and submit to Landlord a written estimate of the 
amount of the remaining Tenant Improvement Costs and the amount of the Tenant 
Improvement Allowance still available to defray such costs (after preparation 
of the Preliminary Plans and Working Drawings).  If such estimate exceeds the 
Tenant Improvement Allowance then still available, Tenant shall pay for all 
such excess costs ("Excess Costs"), in coordination with the monthly 
disbursement schedule outlined in Section 5(b), by paying to Landlord twenty 
(20) days prior to each disbursement by Landlord the amount(s) Landlord needs 
to pay each such monthly and final disbursement pursuant to Section 5(b).  In 
the event the Tenant Improvement Costs are less than the Tenant Improvement 
Allowance, the difference shall be retained by Landlord.

7.   CHANGE ORDERS.  Tenant may from time to time request and obtain change 
orders during the course of construction provided that:  (i) each such 
request shall be reasonable, shall be in writing and signed by or on behalf 
of Tenant, and shall not result in any structural change in the Building, as 
reasonably determined by Landlord except as contemplated by the approved 
Working Drawings, and (ii) all additional charges and costs, including 
without limitation architectural and engineering costs, construction and 
material costs, and processing costs of any governmental entity shall be paid 
out of the Tenant Improvement Allowance, to the extent available, and 
otherwise shall be the sole and exclusive obligation of Tenant, and shall be 
paid by Tenant to Landlord within twenty (20) days after Landlord's request 
therefor.

8.   TENANT DELAYS.  In no event shall the Commencement Date of the Third 
Amendment with respect to the First Additional Premises be extended or 
delayed.

9.   TRADE FIXTURES AND EQUIPMENT.  Tenant acknowledges and agrees that 
Tenant is solely responsible for obtaining, delivering and installing in the 
First Additional Premises all necessary and desired furniture, trade 
fixtures, equipment and other similar items, and that Landlord shall have no 
responsibility whatsoever with regard thereto.  Tenant further acknowledges 
and agrees that neither 

                                      B-4

<PAGE>

the Commencement Date of the Third Amendment nor the payment of Rent shall be 
delayed for any period of time whatsoever due to any delay in the furnishing 
of the First Additional Premises with such items.

10.  FAILURE OF TENANT TO COMPLY.  Any failure of Tenant to comply with any 
of the provisions contained in this Work Letter shall be deemed a default 
under the Third Amendment.  In addition to the remedies provided to Landlord 
in this Work Letter upon the occurrence of such a default by Tenant, Landlord 
shall have all remedies available at law or equity against a defaulting 
tenant pursuant to a written contract, including but not limited to those set 
forth in the Third Amendment.

11.  INSPECTION BY LANDLORD.  Landlord shall have the right to inspect the 
Tenant Improvements at all times; provided, however, that Landlord's failure 
to inspect the Tenant Improvements shall in no event constitute a waiver of 
any of Landlord's rights hereunder, nor shall Landlord's inspection of the 
Tenant Improvements constitute Landlord's approval of the same.  Should 
Landlord reasonably disapprove any portion of the Tenant Improvements, 
Landlord shall notify Tenant in writing of such disapproval and shall specify 
the items disapproved.  Any defects or deviations in, and/or disapproval by 
Landlord of, the Tenant Improvements shall be rectified, if necessary, by 
Tenant at no expense to Landlord; provided, however, that in the event 
Landlord determines that a defect or deviation exists or disapproves of any 
matter in connection with any portion of the Tenant Improvements and such 
defect, deviation or matter might adversely affect the mechanical, 
electrical, plumbing, heating, ventilating and air-conditioning or 
life-safety systems of the Building, the structure or exterior appearance of 
the Building or any other tenant's use of such other tenant's leased 
premises, Landlord may, after first requesting Tenant to cure such default, 
deviation and/or matter, take such action as Landlord reasonably deems 
necessary, at Tenant's expense and without incurring any liability on 
Landlord's part, to correct any such defect, deviation and/or matter, 
including, without limitation, causing the cessation of performance of the 
construction of the Tenant Improvements until such time as the defect, 
deviation and/or matter is corrected to Landlord's reasonable satisfaction.

12.  MISCELLANEOUS.

     (a)  TENANT'S REPRESENTATIVE.  Tenant has designated Wirt Design Group 
as its sole representative with respect to the matters set forth in this Work 
Letter, who, until further notice to Landlord, shall have full authority and 
responsibility to act on behalf of the Tenant as required in this Work Letter.

     (b)  LANDLORD'S REPRESENTATIVE.  Landlord has designated Insignia/ESG as 
its sole representative with respect to the matters set forth in this Work 
Letter, who, until further notice to Tenant, shall have full authority and 
responsibility to act on behalf of the Landlord as required in this Work 
Letter.

     (c)  TIME OF THE ESSENCE.  Unless otherwise indicated, all references 
herein to a "NUMBER OF DAYS" shall mean and refer to calendar days.  In all 
instances where Tenant is required to approve or deliver an item, if no 
written notice of approval is given or the item is not delivered within the 
stated time period, then Tenant shall be deemed to have approved the same.

                                      B-5

<PAGE>

                                 EXHIBIT B-1
                                          
                              SCHEDULE OF DATES