LEASE MODIFICATION AGREEMENT


         THIS LEASE  MODIFICATION  AGREEMENT (this  "Agreement") dated this 12th
day of July,  1999 by and  between  OLD POST ROAD  ASSOCIATES,  LLC,  a New York
limited liability company, having an address at c/o Alfred Weissman Real Estate,
Inc., 1 Larkin Plaza, Yonkers, New York 10701 ("Landlord") and MOBIUS MANAGEMENT
SYSTEMS,  INC., a Delaware corporation,  having an address at 120 Old Post Road,
Rye, New York ("Tenant").

                                   WITNESSETH

         WHEREAS,  Landlord and Tenant  entered into that certain Lease dated as
of December 4, 1997,  as modified  by that  certain  letter  dated March 5, 1998
correcting  the name of the  Landlord  and the  mailing  address of the  Demised
Premises  (collectively,  the  "Lease")  pursuant  to which  Tenant  leased from
Landlord that certain  office  building  known as and by street  address 120 Old
Post Road,  Rye, New York (the  "Building")  and all of the land and improvments
thereon  owned or  groundleased  by Landlord as more  particularly  described in
Exhibit  A  attached  to and made a part of the  Lease  (the  "Real  Property"),
including,  in addition, any other parcels of land or improvements or facilities
serving the Demised  Premises  and made  available  by  easement,  agreement  or
otherwise (together the Real Property and the Building are herein referred to as
the "Demised Premises"); and

         WHEREAS,  Tenant has  requested  Landlord's  approval for the making of
certain  structural  Alterations to the Demised  Premises such that the Building
would  be  expanded  by  the  addition  thereto  of  a  third  floor  containing
approximately  26,800 rentable square feet of space for Tenant's  occupancy (the
"Additional   Space")   together   with   certain   related  site  and  off-site
improvements; and

         WHEREAS, Landlord agrees that Tenant may construct the Additional Space
and Landlord  agrees to consent  thereto upon the terms and conditions set forth
in this Agreement; and

         WHEREAS,  in order to set forth the  terms,  covenants  and  conditions
pursuant to which the  Additional  Space shall be  constructed  and  occupied by
Tenant,  Landlord  and  Tenant  desire to modify the Lease as  provided  in this
Agreement; and

         WHEREAS,  all terms which are  capitalized in this  Agreement,  but not
defined herein, shall have the meanings given to such terms in the Lease.

         NOW,  THEREFORE,  in consideration of One Dollar ($1.00) and the mutual
covenants   contained  in  this  Agreement  and  for  other  good  and  valuable
consideration,  the receipt  and  sufficiency  of which is hereby  acknowledged,
Landlord and Tenant hereby agree as follows:

Section 1.        Construction of Additional Space.

(a)  General.   The  foregoing  recitals  are  hereby  incorporated  herein.  In
connection with the construction of the Additional Space,  Landlord has obtained
the Approvals (as defined below),  and will attempt to obtain the  Architectural
Review Approval,  Building Permit and Lender Approval (as such terms are defined
below).  In addition,  Landlord  arranged for the preparation of the Final Plans
and Specifications  (as defined below).  Tenant will enter into the Construction
Contract (as defined below).  With respect to the construction of the Additional
Space and related site and off-site improvements,  Article 15 of the Lease shall
be of no force or effect.

(b)  Zoning  Approvals.  Attached  hereto as Exhibit A is a site plan (the "Site
Plan")  showing the  Additional  Space  together  with certain site and off-site
improvements related thereto (including, without limitation,  additional parking
for 90  automobiles)  and  which has been  submitted  by  Landlord  on behalf of
Landlord  and  Tenant  to  the  applicable  City  of  Rye  planning  and  zoning
authorities and which has been approved by such authorities  (the  "Approvals"),
subject (i) to a final  approval (the  "Architectural  Review  Approval") of the
City of Rye  Architectural  Review Board (the "Review Board") of the Final Plans
and  Specifications (as hereinafter  defined);  and (ii) to obtaining a building
permit allowing  construction of the Additional Space to commence (the "Building
Permit").  Landlord promptly shall submit the Final Plans and  Specifications to
the appropriate authorities in order to obtain the Architectural Review Approval
and the Building Permit.  Landlord and Tenant  anticipate making such submission
on or before June 22, 1999. After such submission,  Landlord shall make diligent
efforts to obtain the  Architectural  Review Approval and the Building Permit in
accordance  with the  schedule  previously  submitted  by  Landlord  to  Tenant,
including,  without  limitation,  attending  public or private meetings with the
appropriate  officials and filing any necessary additional  documents.  Landlord
shall request that the Review Board  schedule  discussion of the Final Plans and
Specification  on the  agenda of the  earliest  possible  public  meeting of the
Review Board after the submission.  Tenant shall cooperate with Landlord and the
Review Board (at no additional  material cost to Tenant) in connection  with all
such submissions and the attempt to obtain the Architectural Review Approval and
the Building Permit, including, without limitation,  attending and participating
in public and private  meetings.  If Landlord has not obtained the Architectural
Review Approval and the Building Permit (if the Architectural Review Approval or
the Building Permit are obtained, subject only to deminimus changes to the Final
Plans and  Specifications,  the same shall be deemed obtained and Landlord shall
have such deminimus  changes made to the Final Plans and  Specifications)  on or
before  September 21, 1999,  then either  Landlord or Tenant may terminate  this
Agreement by written notice to the other in which event this Agreement  shall be
deemed  null  and  void  and of no force  or  effect;  provided,  however,  such
termination shall have no effect on the Lease,  which shall remain in full force
and effect as if this  Agreement  had never been  executed;  provided,  further,
however,  that  Landlord  shall not have the right to terminate  this  Agreement
unless Landlord concludes,  in its reasonable judgment, that either (or both) of
the  Architectural  Review  Approval or the Building Permit are not likely to be
obtained or the Architectural  Review Approval or the Building Permit are likely
to be obtained,  but only after incurring  additional  costs which are more than
deminimus or only upon certain  required  conditions or changes which will cause
an  increase  in costs to  construct  the  Additional  Space  that is more  than
deminimus.  If the  Architectural  Review  Board  approves  the Final  Plans and
Specifications  subject to changes thereto which are more than deminimus,  or if
issuance of the Building  Permit is subject to conditions,  the cost of which to
satisfy is more than  deminimus,  Landlord's  right to terminate  this Agreement
shall be subject to nullification by Tenant, if Tenant, within ten (10) business
days of  Landlord's  termination,  shall agree in writing to pay any  additional
cost associated with such requested  changes.  If neither party  terminates this
Agreement, then Landlord shall continue diligently to pursue the Building Permit
and the Architectural Review Approval.

(c) Plans and Specifications.  Attached hereto as Exhibit B is a schedule of the
final plans and specifications (the "Final Plans and  Specifications"),  subject
to any revision which may be required by the applicable  authorities in order to
obtain the Architectural  Review Approval and the Building Permit,  prepared for
Landlord  and  Tenant  by  Dennis  Noskin &  Associates  as the  architect  (the
"Architect"),  for the construction of the Additional Space, including,  without
limitation,  all  of  the  related  site  and  off-site  improvements.  Landlord
acknowledges  that Tenant has retained the  services,  at Tenant's sole cost and
expense and not as a part of the Cost of Construction  (as defined below),  of a
structural   engineer  to  review  on  Tenant's   behalf  the  Final  Plans  and
Specifications.  In the event that such engineer  shall  request  changes to the
Final Plans and Specifications,  Landlord agrees to consider such changes and to
discuss the need for such  changes with  Tenant's  engineer.  However,  Landlord
shall be under no obligation to have the Final Plans and Specifications  revised
based upon such request or such discussions.  The cost of the preparation of the
Final  Plans and  Specifications  shall be included as a line item in the Budget
(as  defined  below).  Neither  the  approval by Landlord of the Final Plans and
Specifications  or any other  plans,  specifications,  drawings  or other  items
associated with the Additional  Space shall  constitute any warranty or covenant
by Landlord to Tenant,  except for any warranty or covenant  expressly set forth
in this  Agreement,  of the adequacy of the design for Tenant's  intended use of
the  Additional  Space.  Tenant  agrees to,  and does  hereby,  assume  full and
complete responsibility to ensure that the floor plans and general layout of the
Additional Space as shown on the Final Plans and  Specifications are adequate to
fully meet the needs and  requirements  of Tenant's  intended  operations of its
business  within  the  Additional   Space.   Landlord   acknowledges   that  the
Construction  Contract (as defined below) permits Tenant to make certain changes
to the Plans and Specifications, as "Change Orders" to the work. Tenant shall be
permitted to make such changes,  provided that Tenant shall be  responsible  for
the actual  additional  costs relating  thereto as set forth in the Construction
Contract.

(d) Budget. Attached hereto as Exhibit C is a budget (the "Budget"),  broken out
by line  item  category,  showing  an  aggregate  cost  equal to  Three  Million
Twenty-five Thousand Four Hundred and 00/100 Dollars  ($3,025,400.00) (the "Cost
of Construction")  required to complete construction of the Additional Space and
the  related  site and  off-site  improvements  shown  on the  Final  Plans  and
Specifications.  The Budget  shall be used as a basis for the making of Advances
(as defined  below).  Notwithstanding  the foregoing,  Landlord and Tenant agree
that the following items shown on the Final Plans and Specifications are "extra"
items  requested by Tenant and that the cost of such items is in addition to the
Cost of  Construction  and shall be at the sole cost and expense of Tenant:  (i)
the front stairway,  (ii) the four (4) shower stalls and all necessary plumbing,
tile work and  accessories  thereto  and (iii)  the  men's and  women's  lockers
associated  with  the  showers.  The  cost of such  items  shall be added to the
Construction  Account and shall be subject to Advances as provided herein and in
the  Construction  Contract.  Landlord  has  agreed  to pay the fees of  certain
professionals,   including  without   limitation  the  Architect,   retained  in
connection with obtaining the Approvals,  the Architectural  Review Approval and
the Building  Permit and with completing the Additional  Space.  Pursuant to the
terms of the Construction  Contract,  General Contractor has agreed to reimburse
Landlord  for such fees in the  event  that the  actual  cost to  construct  the
Additional  Space is less than the Cost of Construction.  Landlord  acknowledges
that  whether  or not funds  are  available  from  General  Contractor  for such
reimbursement, Landlord shall pay all such fees.

(e) General  Contract.  Simultaneously  with the  execution  of this  Agreement,
Tenant  shall  enter  into  a  contract  (the  "Construction  Contract")  for  a
stipulated  sum equal to the Cost of  Construction  with  Alfred  Weissman  Real
Estate, Inc. ("General  Contractor")  pursuant to which General Contractor shall
act as general  contractor in connection with the construction of the Additional
Space   (including,   without   limitation,   all  related   site  and  off-site
improvements)  in  accordance  with the Final Plans and  Specifications.  Tenant
acknowledges that General Contractor is affiliated with Landlord,  but in no way
is General Contractor a partner or joint venturer with Landlord. As used herein,
the term "General  Contractor" shall include such qualified  substitute  general
contractor  as may be  retained  by Tenant in the event of a default  by General
Contractor  under, and as provided in, the Construction  Contract,  and Landlord
hereby consents to Tenant's right to make such substitution.

(f)  Establishment  of  Construction  Account.  In order to ensure Landlord that
Tenant  shall have  funds  available  in order to pay the Cost of  Construction,
Tenant shall establish a separate bank account (the "Construction  Account"), at
a financial  institution  reasonably  acceptable  to Landlord  and Tenant,  into
which, simultaneously with its execution of this Agreement, Tenant shall deposit
a sum equal to the Cost of  Construction  less the Previously  Advanced Fees (as
defined  below).  Upon  execution of this  Agreement,  Tenant  shall  provide to
Landlord  evidence of the  establishment  of such account and from time to time,
upon  request,  evidence of the balance  maintained  therein.  The  Construction
Account shall be established,  and the funds therein shall be held in trust, for
the sole  purpose  of paying  for the costs of  construction  of the  Additional
Space.  Tenant shall not make,  nor permit,  withdrawals  from the  Construction
Account except in accordance with the terms and conditions of this Agreement. In
the event this Agreement is terminated  because  Landlord does not obtain any of
the Architectural  Review Approval,  the Building Permit, the Lender Approval or
the SNDA (as defined  below),  then  Landlord  shall  release all of  Landlord's
rights in the Construction Account.

(g) Withdrawals from  Construction  Account.  The construction of the Additional
Space  shall  be at the  sole  cost  and  expense  of  Tenant  up to the Cost of
Construction  plus  additional  costs that Tenant is expressly  responsible  for
paying (e.g.  Change Orders,  the  aforementioned  stairway).  Tenant shall make
advances  (each an  "Advance"  and  collectively,  "Advances")  within  ten (10)
Business Days after receipt of a request for an Advance, out of the Construction
Account,  for actual work in place and materials delivered to the Property,  and
in accordance with the applicable  request for Advance and the following further
conditions:

     (i) Tenant  shall not be required to make  Advances  more  frequently  than
twice per month;

     (ii) requests for Advances shall have been received by Tenant not less than
ten (10) Business Days prior to the date such Advance is requested to be made;

     (iii) all requests for an Advance shall be made on the form attached hereto
as Exhibit E, together with  reasonable  evidence (e.g.  invoices and payroll if
applicable)  that the  amounts  requested  are due and shall be  subject  to the
reasonable review and approval  (including,  without limitation,  site visits to
inspect  such work,  the cost of which shall equal $500 per Advance and are part
of the Cost of Construction and will be paid out of the Construction  Account at
the time of the  applicable  Advance) of an engineer  or  inspector  selected by
Tenant  both as to the  work  completed,  materials  delivered  and the  amounts
requested  therefor  and shall be further  subject to the 10%  retainage  and 5%
retainage set forth in the Construction Contract.

     (iv) a certification  from the General  Contractor and the Architect,  that
the work to which such request for Advance  relates has been completed in a good
and workmanlike manner in accordance with the Final Plans and Specifications and
all  applicable  codes  and that  the  balance  of the  funds  remaining  in the
Construction  Account  after making such Advance are  reasonably  expected to be
sufficient  to  complete  the  Additional  Space and related  site and  off-site
improvements  and that there  remains in each line item which is the  subject of
such Advance an amount which is reasonably expected to be sufficient to complete
the work contemplated by such line item;

     (v) copies of  unconditional  lien  waivers or  releases  for all  previous
Advances from the applicable mechanics;

     (vi) with respect to the final  Advance,  the  Certificate of Occupancy (as
hereinafter  defined) has been issued and the work is complete in all  respects;
and

     (vii) with respect to the final  Advance,  evidence  that no  mechanic's or
materialmen's  liens or other liens have been filed against the Demised Premises
in  connection  with  the  construction  of the  Additional  Space  and that the
Architect has delivered a certificate  in form  reasonably  acceptable to Tenant
that the Additional Space and related improvements are complete. Notwithstanding
anything to the contrary  contained  in this  Agreement,  Tenant has  previously
advanced the following sums (the  "Previously  Advanced  Fees"):  (i) $75,000 to
establish the escrow required by the City of Rye in connection with the proposed
traffic  light (ii) $39,000 for  Building  Permit  fees,  and (iii)  $19,000 for
certain other fees. Such amounts shall be reimbursed to Tenant in the event this
Agreement  is  terminated  as a  result  of  a  failure  to  obtain  either  the
Architectural  Review Approval,  the Building Permit, the Lender Approval or the
SNDA.

     (h)  Depreciation.  During the term of the  Lease,  Tenant  alone  shall be
entitled  to  claim  depreciation  on the  Additional  Space  for  all  taxation
purposes.

     Section 2. Definitions. The definitions contained in Article 1 of the Lease
are hereby modified as follows:

     (a)  Additional  Space  Completion  Date:  The date on which a temporary or
permanent  certificate  of  occupancy  is issued  by the City of Rye  permitting
Tenant to occupy  the  Additional  Space for the  conduct of its  business  (the
"Certificate of Occupancy").

(b) Building:  The office  building  known as and by street address 120 Old Post
Road,  Rye,  New  York,  including,   without  limitation,   when  substantially
completed, the Additional Space.

(c) Tenant Delay:  A Tenant Delay shall include a delay in the completion of the
Additional  Space as a result of an event  described in Section 3.3 of the Lease
(except,  Landlord  acknowledges  that all  plans and  specifications  have been
timely  submitted).  All  references to Landlord's  Work in such Section 3.3, in
addition, shall be references to the Additional Space.

Section 3. Term. On the Additional  Space Completion Date, the Term of the Lease
automatically will be extended such that the Expiration Date shall be 11:59 p.m.
on  the  day  before  the  tenth  (10th)  anniversary  of the  Additional  Space
Completion  Date,  or upon such  earlier  date as the Term shall be  canceled or
terminated  pursuant to any of the  conditions  or  covenants  of the Lease,  or
pursuant to law.

Section 4. Rent.  In Section  2.3(a) of the Lease,  the  reference to Lease Year
6-10 is amended  to refer to Lease Year  6-Expiration  Date.  Commencing  on the
Additional  Space  Completion  Date,  in  addition  to the Fixed Rent  currently
specified  in Section  2.3(a) of the Lease,  Tenant  shall pay,  throughout  the
balance  of the Term  (subject  to  adjustment  during  any  renewal  periods as
provided  below),  Fixed  Rent in  respect  of the  Additional  Space  equal  to
$50,000.00  per  annum,  payable in equal  monthly  installments  of  $4,166.67.
Landlord  and Tenant  acknowledge  that the Fixed Rent payable in respect of the
Additional  Space (but, not the Fixed Rent or Additional Rent payable in respect
of the  remainder  of the  Demised  Premises)  is subject  to certain  rights of
abatement and offset in favor of Tenant as set forth in that certain  Landlord's
Undertaking and Indemnity Agreement of even date herewith.

Section 5.  Additional  Rent.  With respect to the Additional  Space,  it is the
intent  of  Landlord  and  Tenant  that the  Fixed  Rent  shall be a net rent to
Landlord,  except as specifically set forth herein.  Therefore,  the Real Estate
Tax Base and the Base  Operating  Year  shall  remain as set forth in the Lease.
Tenant  shall  continue to pay all  increases in Real Estate Taxes over the Real
Estate Tax Base and all Operating  Expenses over the Operating  Expenses for the
Base Operating  Year whether or not same are applicable to the Additional  Space
or to the premises initially demised to Tenant under the Lease.

Section 6. Subordination. Prior to, and as a condition of, any withdrawal of any
amount from the  Construction  Account and in any event no later than  September
21,  1999,  Landlord  shall  obtain  from its  current  lender a  subordination,
nondisturbance  and attornment  agreement,  (the "SNDA")  covering the terms and
conditions of this Agreement and Tenant's  occupancy of the Additional  Space in
form and substance reasonably acceptable to Tenant and Landlord shall cause such
agreements to be recorded in the County clerk's  Office in  Westchester  County.
Together  with  Landlord's  request  for the  Lender  Approval  (as  hereinafter
defined)  Landlord  shall  submit  to such  lender  the  form of  subordination,
non-disturbance  and attornment  agreement  attached  hereto as Exhibit D, which
form will be used as the basis of  negotiation  with such  lender.  Landlord and
Tenant shall  execute and deliver  same  promptly  upon receipt  thereof by such
lender to the extent reasonably acceptable to each of them.

Section 7. Assignment and Subletting.  Notwithstanding  anything to the contrary
contained in Sections  6.1(a),  6.4, 6.6 and 6.8 of the Lease, in respect of the
Additional Space, the following terms and conditions shall apply:

(a) No Consent  Required.  Tenant shall have the right to sublet the  Additional
Space  without the consent of  Landlord,  provided,  however,  Tenant shall give
Landlord  written notice of such  subletting no less than ten (10) business days
prior to the effective  date thereof.  Any sublease of all or any portion of the
Additional  Space shall comply with the terms and conditions of Sections 6.5 and
6.7 of the Lease.  Notwithstanding any such sublease,  Tenant shall remain fully
liable for the  payment of Fixed  Rent or  Additional  Rent due or to become due
pursuant  to the  Lease  and  this  Agreement  and  for the  performance  of all
obligations,  covenants, agreements, terms and conditions contained in the Lease
and this Agreement.

(b)  Consideration.  In the case of a sublease of the Additional  Space,  Tenant
shall pay to Landlord  as  Additional  Rent,  fifty  percent  (50%) of any rent,
additional  charge  or other  consideration  paid by the  subtenant  which is in
excess of the sum of (i) an amount equal to the Fixed Rent and  Additional  Rent
that Tenant then currently pays,  calculated on a per square foot basis, for the
portion of the  Demised  Premises  located on the first and second  floor of the
Building,  plus  (ii)  Tenant's  reasonable  out-of-pocket  costs  and  expenses
incurred  in  connection  with such  sublease,  including,  without  limitation,
commissions,  legal fees and construction expenses. For example, assume that (i)
Tenant  pays Fixed Rent and  Additional  Rent on each of the first two floors at
the  aggregate  rate of $25.00  per  rentable  square  foot,  (ii)  that  Tenant
subleases the third floor for an aggregate rental of $30.00 per square foot, and
(iii) that Tenant  incurred no costs in  connection  with such  sublet.  In such
event Tenant would  receive  $27.50 per rentable  square foot of such rent (i.e.
$25 plus 50% of $30-$25) and Landlord  would  receive $2.50 (50% of $30-$25) per
rentable  square  foot.  The sums payable  under this  Section  shall be paid to
Landlord  as and when paid by the  subtenant  to  Tenant.  In the  event  Tenant
subleases the  Additional  Space along with all or a portion of the remainder of
the  Demised  Premises in one or more  subleases  to one entity or more than one
entity,  each of which are  affiliates of one another,  then for the purposes of
calculating  the amount due to  Landlord  under  this  subsection  (b) and under
Section  6.8(b) of the  Lease,  the  aggregate  consideration  paid  under  such
sublease(s)  shall be  applied,  on a per square foot  basis,  equally  over the
entire space subleased.

     Section 8.  Memorandum.  The  provisions  of Section 7.2 of the Lease shall
specifically apply to this Agreement.


Section 9. Casualty.  Notwithstanding  anything to the contrary contained in the
Lease (including,  without limitation  Section 10.2 thereof),  in the event of a
casualty of all or any portion of the Demised Premises (except a casualty during
the Second Option Period,  as defined below),  including,  without  limitation a
casualty during  construction of the Additional Space,  Landlord shall repair or
rebuild the Demised  Premises  as  provided in Section  10.1 of the Lease.  With
respect to any casualty  during the Second  Option  Period,  the  provisions  of
Article 10 of the Lease shall apply as though not modified by this Agreement.

Section 10. Condemnation.  Notwithstanding anything to the contrary contained in
the Lease,  in the event that a condemnation  of all or a portion of the Demised
Premises  results  in the  termination  of the  Lease  pursuant  to the terms of
Sections 12.1 or 12.2 thereof, then, notwithstanding Section 12.3 thereof to the
contrary, any award for such condemnation shall be paid as follows:

     (a) first,  to any Superior  Mortgagee in accordance  with the terms of any
Superior Mortgage;

     (b) second,  to Landlord  and Tenant,  equally,  until  Tenant  receives an
amount equal to the then  unamortized cost of the construction of the Additional
Space paid for by Tenant  (amortized  on a straight  line basis over the initial
ten (10) year Term); and

     (c) third, the balance to Landlord.

Notwithstanding anything to the contrary contained in Section 12.2 of the Lease,
Landlord shall not exercise its termination  right  thereunder  unless the award
payable  in  connection  with such  condemnation  is  sufficient  to fully  fund
subsections (a) and (b) above.

Section 11. Repairs.  Subject to Landlord's  right, if any, to be reimbursed for
Operating  Expenses  pursuant  to the Lease  and as  stated in  Section 5 above,
Landlord  shall  be  responsible  for all  repairs  to the  structural  elements
(including,  without limitation,  the Building roof) and building systems in the
Additional Space.

Section 12. Security.  Landlord shall make written request, and thereafter shall
make a good faith attempt,  for a release by the current Superior Mortgagee,  of
the Letter of Credit (the  "Letter of Credit")  currently  in effect as security
for the  Tenant's  obligations  under the Lease and being held by such  Superior
Mortgagee.  In the event that such Superior  Mortgagee  shall deny such request,
for any reason, then the letter of Credit shall remain in effect as security for
Tenant's  performance  of its  obligations  under  the Lease as set forth in the
Lease.

Section 13. Parking.  As part of the  construction of the Additional  Space, the
General   Contractor   shall   construct  the  parking  spaces  and  other  site
improvements  shown on the Site Plan.  Landlord  will  coordinate  with  General
Contractor to ensure that construction of an additional  temporary parking area,
sufficient for the parking of 45  automobiles,  is completed as a portion of the
first  phase  of  construction  and is  available  for  Tenant's  use as soon as
reasonably practicable after construction commences.

Section 14.       Options.


     (a) Existing Option.  At any time that Tenant exercises the Option,  Tenant
shall be deemed to have renewed the Lease with respect to the  Additional  Space
for the Option  Period  (i.e.  the Term of the Lease shall be  extended  for the
entire Demised Premises).

     (i)  Throughout  the Option  Period,  Fixed Rent  payable in respect of the
Additional Space shall equal the following:

  Option Year       Rate Per     Per Annum Fixed Rent          Per Month
                  Square Foot                                  Fixed Rent

       1             $5.00             $134,000                   $11,166.67
       2              5.30              142,040                    11,836.67
       3              5.62              150,616                    12,551.33
       4              5.96              159,728                    13,310.67
       5              6.32              169,376                    14,114.67

(b)      Second Option.

     (i) Provided Tenant is not in default (beyond  applicable  notice and grace
periods)  pursuant to any of the terms and conditions of the Lease,  and further
provided  that Tenant has  exercised  the Option,  Tenant shall have the further
option  (the  "Second  Option")  to renew  the  Lease as to the  entire  Demised
Premises for an additional five (5) year period (the "Second Option Period") for
the period  commencing on the date  following the last date of the Option Period
upon the terms and  conditions  contained in the Lease,  except,  as provided in
this Agreement. To exercise the Second Option, Tenant shall give Landlord notice
(the "Second  Option  Extension  Notice") of the intent to exercise  said Second
Option  not less than  nine (9)  months  prior to the date on which  the  Second
Option Period will commence.  The Second Option  Extension Notice shall be given
as provided in Article 29 in the Lease.  In the event Tenant shall  exercise the
Second Option, the Lease will terminate in its entirety at the end of the Second
Option Period and Tenant will have no further options to extend the Lease.

(ii)     The Fixed Rent for the Second Option shall be determined as follows:

     (A)  Landlord and Tenant will have until the date which is eight (8) months
prior  to the  last  day of the  Option  Period  within  which  to  agree on the
then-fair market rental value of the Demised Premises,  as defined in subsection
(C) below.  If they agree on the Fixed Rent within such period,  they will amend
the Lease by stating the Fixed Rent.


     (B) If  Landlord  and  Tenant are unable to agree on the Fixed Rent for the
Second  Option  Period  within  such time,  then,  the Fixed Rent for the Second
Option  Period will be 90% of the  then-fair  market rental value of the Demised
Premises as determined in accordance with subsection (D) hereof.

     (C) The "then-fair  market rental value of the Demised Premises" means what
a landlord under no compulsion to lease the Demised  Premises and a tenant under
no  compulsion  to lease the  Demised  Premises  would  determine  as Fixed Rent
(including  initial  monthly rent and rental  increases)  for the Second  Option
Period,  as of the  commencement  of  the  Second  Option  Period,  taking  into
consideration the uses permitted under the Lease, the quality,  size, design and
location of the Demised Premises,  and the rent for comparable buildings located
in the  vicinity  of  Westchester  County,  New York and the fact  that the Base
Operating Year and the Real Estate Tax Base shall not change.

     (D) Within  thirty  (30) days after the  expiration  of the thirty (30) day
period set forth in subsection (B) above, Landlord and Tenant shall each appoint
one licensed real estate  appraiser,  and the two appraisers so appointed  shall
jointly attempt to determine and agree upon the then fair market rental value of
the  Demised  Premises.  If they are  unable to agree,  then each  appraiser  so
appointed shall set one value, and notify the other appraiser,  of the value set
by him or her,  concurrently  with such appraiser's  receipt of the value set by
the other  appraiser.  The two appraisers then shall,  together,  select a third
licensed  appraiser  (or if the two  appraisers  cannot  agree  upon such  third
appraiser,  then such third appraiser shall be selected  pursuant to arbitration
as  provided  under  Article 30 of the Lease),  who shall  choose one of the two
values set by the first two  appraisers  as the fair market  rental value of the
Demises  Premises,  after  reviewing  the  reports  of the first two  appraisers
appointed by the parties,  and after doing such  independent  research as he/she
deems appropriate.

Section 15.       Miscellaneous.

(a) Lease Ratified.  Except as expressly  modified by this Agreement,  the Lease
remains  unmodified  and is hereby  ratified and  confirmed  and remains in full
force and effect.  Any reference to the Lease whether in the Lease or otherwise,
shall mean the Lease as modified by this Agreement.

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

(c) Headings.  All section  headings used in this Agreement are for  convenience
only and in no way  define,  limit or  describe  the  scope  or  intent  of this
Agreement, nor in any way affect the terms of this Agreement.

(d) Lender  Consent  Required.  This  Agreement and the  obligations  and rights
contained  herein are subject to and contingent upon Landlord  obtaining (i) the
written consent to this Agreement of the current Superior Mortgagee (the "Lender
Approval")  and (ii) the SNDA,  executed by Lender and  Landlord  in  recordable
form. Promptly after the execution hereof,  Landlord shall submit this Agreement
to such Superior Mortgagee for consent and Landlord  thereafter shall diligently
and in good faith pursue same. In the event that such Superior Mortgagee refuses
to grant such Lender  Approval or provide the SNDA and if a  Termination  Notice
(as defined  below) is given,  this  Agreement  shall be null and void and of no
force or effect;  provided however, in such event the Lease shall remain in full
fore and effect as if this  Agreement had never been  executed.  If Landlord and
Tenant have not received the Lender Approval and SNDA on or before September 21,
1999,  then either  Landlord or Tenant  shall have the right to  terminate  this
Agreement  by  giving  written  notice  (the  "Termination  Notice")  (provided,
however,  only Tenant shall have the right to give a  Termination  Notice if the
Lender  Approval is received,  but Lender does not provide the SNDA)  thereof to
the other party. No withdrawal may be made from the  Construction  Account until
the Lender  Approval and SNDA (unless the  requirement for the SNDA is waived by
Tenant) are received.

(e) Brokers. Landlord and Tenant each covenant that they have not dealt with any
real  estate  broker  or  finder  with  respect  to this  Agreement  other  than
Insignia/Rostenberg  Doern  ("Insignia")  and Cushman & Wakefield  ("C&W").  Any
commission  relating to this  Agreement  which may be payable to Insignia or C&W
(either directly or through an agreement  between C&W and Insignia)  pursuant to
the separate agreement (the "Broker Agreement") between Landlord and Insignia at
or about the time that the Lease was executed, shall be paid by Landlord. Tenant
acknowledges  that any fees or  commissions  due and payable to C&W by reason of
any new arrangement or agreement between C&W and Tenant shall be paid by Tenant.
Each  party  shall  hold the other  party  harmless  from all  damages,  claims,
liabilities  or  expenses,  including  reasonable  and  actual  attorneys'  fees
(through  all levels of  proceedings),  resulting  from any  claims  that may be
asserted  against the other party by any real estate  broker or finder with whom
the  indemnifying  party either has or is purported to have dealt  including the
parties stated above.

(f) Insurance.  At the time that the Additional Space is Substantially Complete,
Landlord  will  increase any limits in respect of the  insurance  required to be
carried by Landlord  under  Section 11.1 of the Lease to an amount which insures
the then full replacement cost of the Building.

         IN WITNESS WHEREOF,  the parties have executed this Agreement as of the
date first written above.

     TENANT:            MOBIUS MANAGEMENT SYSTEMS, INC.



                             By: /s/ E. Kevin Dahill
                        Name:   E. Kevin Dahill
                         Title: Chief Financial Officer

    LANDLORD:           OLD POST ROAD ASSOCIATES, LLC



                             By: /s/ Alfred Weissman
                        Name:   Alfred Weissman
                        Title:  Managing Member



<PAGE>



                                    EXHIBIT A

                                    SITE PLAN






<PAGE>



                                    EXHIBIT B

                                   SCHEDULE OF
                         FINAL PLANS AND SPECIFICATIONS


     1.  construction   documents  and  specifications   prepared  by  Landscape
Architectural Design Associates, PC dated June 1, 1999 (drawings L1 though L9)

     2. construction documents prepared by TRC Raymond Key Associates dated June
15, 1999 (drawings L10 and L11)

     3. Block and Lot Sheet 146.13

     4. base bid parking drainage drawings (L3 and L10) and

     5. site specifications

     6. Architectural Drawings C1, C2, A-2.0A, A-2.0, A-21, A-2.2, A-2.3, A-2.4,
A-2.5, A-2.6, A-3.0, A-3.1, A-5.0, A-5.1, A-5.2, A-5.3, A-6.0, A-6.1, and A-6.2

     7. Structural Drawings S-1 and S-2

     8. Mechanical Drawings M-1, M-2, M-3, and M-4

     9. Plumbing Drawings P-1, and P-2

     10. Electrical Drawings E-1, E-2 and E-3

     11. Mechanical Specifications and Addendum #1 prepared by CIMA Group.







<PAGE>





                                    EXHIBIT C

                                     BUDGET




<PAGE>





                                    EXHIBIT D

             SUBORDINATION, NON-DISTURBANCE AND ATTORNMENT AGREEMENT

<PAGE>



                                    EXHIBIT E

FORM






<PAGE>