<PAGE>
                                                                 Exhibit 10.9(a)



                                  OFFICE LEASE






                             SPECTRA OFFICE COMPLEX




                           SPECTRA DEVELOPMENT COMPANY
                             2593 WEXFORD-BAYNE ROAD
                               SEWICKLEY, PA 15143



<PAGE>


                                      INDEX

================================================================================
<TABLE>
<CAPTION>

<S>             <C>                                                                                          <C>
ARTICLE         TITLE                                                                                        PAGE
    1           PREMISES......................................................................................1

    2           DEFINITIONS...................................................................................1

    3           TERM..........................................................................................3

    4           BASE RENT.....................................................................................4

    5           OPERATING EXPENSES, TAXES, OTHER CHARGES......................................................5

    6           USE...........................................................................................6

    7           PRIOR OCCUPANCY/ POSSESSION...................................................................7

    8           TERMINATION, EXTENSION, HOLD-OVER.............................................................7

    9           PLACE OF PAYMENT..............................................................................7

   10           LESSEE'S COVENANTS............................................................................8

   11           SERVICES AND EQUIPMENT........................................................................8

   12           ELECTRICITY..................................................................................10

   13           LESSOR'S AND LESSEE'S WORK...................................................................11

   14           REPAIRS......................................................................................11

   15           INSURANCE REQUIREMENTS.......................................................................12

   16           OBSERVANCE OF RULES/REGULATIONS AND COVENANT OF QUIET ENJOYMENT..............................13

   17           LIABILITY OF LESSOR; INDEMNIFICATION; AND EXCUSE OF PERFORMANCE..............................14

   18           DAMAGE BY FIRE AND OTHER CAUSE...............................................................16

   19           CONDEMNATION.................................................................................17

   20           ENTRY........................................................................................18
</TABLE>


<PAGE>

<TABLE>

<S>             <C>                                                                                          <C>
   21           RIGHT TO CHANGE PUBLIC PORTIONS OF BUILDING..................................................18

   22           BANKRUPTCY...................................................................................18

   23           DEFAULTS/ REMEDIES/ DAMAGES..................................................................19

   24           ASSIGNMENT/ MORTGAGING/ SUBLEASING AND RECAPTURE.............................................22

   25           SUBORDINATION................................................................................23

   26           RIGHTS OF HOLDER OF MORTGAGE IN EVENT OF DEFAULT BY LESSOR...................................23

   27           SURRENDER OF PREMISES........................................................................24

   28           EFFECT OF CONVEYANCE BY LESSOR...............................................................24

   29           NOTICES......................................................................................24

   30           WAIVER OF REDEMPTION.........................................................................25

   31           ESTOPPEL CERTIFICATE.........................................................................25

   32           MISCELLANEOUS................................................................................25

   33           RELOCATION...................................................................................27
</TABLE>

                         EXHIBIT   "A"  FLOOR PLAN
                         EXHIBIT   "B"  SITE PLAN
                         EXHIBIT   "C"  BUILDING SERVICES
                         EXHIBIT   "D"  BUILDING STANDARDS
                         EXHIBIT   "E"  RULES AND REGULATIONS
                         EXHIBIT   "F"  BUILDOUT AGREEMENT


<PAGE>




                           SPECTRA OFFICE BUILDING II

                                 LEASE AGREEMENT
                                 ---------------


         THIS LEASE AGREEMENT ("Lease") made the 18 day of August, 1994, by and
between Spectra Development Company (the "Lessor") and THE NOMOS CORPORATION
(the "Lessee").

                              ARTICLE I - PREMISES
                              --------------------

         SECTION 1.01 In consideration of the rents, charges, covenants and
agreements herein contained, Lessor hereby demises and lets unto Lessee, and
Lessee does hereby rent hire, take and lease from Lessor, all that portion of
Spectra Office Building II ("Building") located on 2591 Wexford-Bayne Road,
Franklin Park Borough, Sewickley, Pennsylvania 15143, particularly described
herein as follows: THAT AREA SITUATED ON THE FIRST, THIRD AND FOURTH FLOORS
CONSISTING OF 17,489 RENTABLE SQUARE FEET (the "Premises") and shown on the plan
attached hereto as Exhibit "A", together with the right to use, in common with
others, the common areas of the building.

         TO HAVE AND TO HOLD unto the Lessee, its permitted successors and
assigns for the Term of this lease; but subject and subordinate to all
agreements, covenants and conditions of record which affect the Building and/or
the land on which the building is located.

         SECTION 1.02 The Premises referred to in Section 1.01 comprises of
17,489 square feet of rentable area (the "Rentable Area").


                             ARTICLE 2 - DEFINITIONS
                             -----------------------

         SECTION 2.01 The terms defined in this Article shall, for all purposes
of this Lease, and all agreements supplemental hereto, have the meanings herein
specified unless the context otherwise requires. Such definitions shall be
applicable to both the singular and plural use of such terms.

              (a) "Additional Rent" shall have the definition set forth in
Article 5.

              (b) "Base Rent" shall have the definition set forth in Section
4.01.

              (c) "Building" shall mean the multi-story office building with
concourse and basements together with the warehouse and plazas constructed on
the Land at 2591 Wexford Bayne Road, Franklin Park Borough, Sewickley,
Pennsylvania 15143, known as Spectra Office Building II.

              (d) "Commencement Date" shall mean the following date: August 13,
1994 August 15, 1994

              (e) "Default Rate" shall mean interest at the rate equal to the
lesser of (i) the highest rate permitted by law or (ii) two percent (2%) per
annum above the Prime Rate.


<PAGE>



              (f) "Holidays", whenever used in this Lease, shall mean, as of the
date of this lease, those days generally observed in the City of Pittsburgh,
Pennsylvania as New Years Day, Memorial Day, Independence Day, Labor Day,
Thanksgiving Day and Christmas Day. If, during the term of this lease, the paid
holidays observed by the maintenance employees at the Building should change,
the definition of "Holidays" shall then change accordingly without changing the
validity of this Lease.

              (g) N/A

              (h) "Land" shall mean the property described in Exhibit "B".

              (i) "Lease Year" shall mean each calendar year during the term and
any renewals thereof.

              (j) "Lessee's Percentage of Office Expenses" shall be that
percentage determined by dividing the Rentable Area of the Premises by the
Office Area, which percentage is computed to be 0%, LESSEE WILL HAVE NO SHARE OF
OFFICE EXPENSE.

              (k) "Lessees Percentage of Taxes" shall be that percentage
determined by dividing the Rentable Area of the Premises by the total square
feet of the building which percentage is computed to be 55.11%.

              (l) "Normal Business Hours" shall mean from 7:30 A.M. to 6:00 P.M.
weekdays (Saturdays, Sundays and Holidays excepted).

              (m) "Office Area" shall mean the office portion of the building,
which is stipulated to contain 31,736.00 square feet of Rentable Area.

              (n) "Office Expenses" shall mean that portion of the Operating
Expenses allocable to the Office Area as determined by Lessor whose
determination shall be deemed conclusive.

              (o) "Operating Expenses" are defined as (i) all those expenses of
every kind and character actually incurred during each year in respect of the
operation, management, maintenance, replacement and repair of the Land and
Building in accordance with accepted principals of sound management and
accounting practices as applied on a consistent basis to the operation,
management, maintenance, replacement and repair of first class office buildings,
including without limitation premiums for all insurance carried by Lessor, plus
(ii) those additional expenses which Lessor reasonably determined it would have
so incurred during each year had the Building been 100% occupied. Operating
Expenses shall include without limitation utility expenses, labor, contracted
labor, insurance, materials, fees and licenses, management fees, sales and use
taxes and capital expenditures which will effect savings in Operating Expenses
amortized over the useful life of the improvement. Operating Expenses shall not
include real estate brokerage and leasing commissions; expenses incurred in
procuring new tenants; capital expenditures other than as set forth above; cost
of improvements to premises of other lessees; interest and principal payments on
mortgages; ground rental payments; expenses in connection with maintaining and
operating the parking garage; real estate taxes, assessments or charges; and
expenses for repairs or other work occasioned by fire, windstorm or other
insured casualty. There will be no "Operating Expenses" for the 11,982 square
feet of rentable area.


                                      -2-
<PAGE>


              (p) "Partial Lease Year" shall mean any partial calendar year
during the Term and any renewals thereof.

              (q) "Premises" shall mean the space described in Article 1.

              (r) "Prime Rate" shall mean from time to time the interest rate
per annum announced or published by Mellon Bank, N.A., of Pittsburgh,
Pennsylvania, as it's prime rate as in effect at the close of business on the
first business day such rate Of interest is assessable in accordance with the
terms of this lease.

              (s) "Rent" or "Rental" shall include Base Rent, Additional Rent
and all other sums which may become due by Lessee under this Lease.

              (t) "Rentable Area of Lessee" or "Rentable Area" shall have the
definition set forth in Section 1.02.

              (u) "Taxes" shall mean all federal state and local governmental
taxes, assessments and charges (including general real estate taxes, assessment)
of every kind or nature, other than sales or use taxes, which Lessor shall pay
or become obligated to pay because of or in connection with the ownership,
leasing, management, control or operation of the Building and the Land or of the
personal property, fixtures, machinery, equipment, systems or apparatus located
therein or used in connection therewith (including any rental or similar taxes,
such as the Pittsburgh Business Privilege Tax, and license, building, occupancy,
permit or similar fees levied in lieu of or in addition to general real or
personal property taxes). For purposes hereof Taxes for any year shall be Taxes
which are due for payment or paid in that year rather than Taxes which are
assessed or become a hen during such year. There shall be included in Taxes for
any year the amount of all fees, costs and expenses (including reasonable
attorneys' fees) paid by Lessor during such year in seeking or obtaining any
refund or reduction of Taxes. Taxes in any year shall be reduced by the net
amount of any tax refund received by lessor during such year in seeking or
obtaining any refund or reduction of Taxes. Taxes in any year shall be reduced
by the net amount of any tax refund received by Lessor during such year.

         Taxes shall not include any federal, state or local sales, use,
franchise, capital stock, inheritance, general income, gift or estate taxes,
except that if a change occurs in the method of taxation resulting in whole or
in part of the substitution of any such taxes, or any other assessment, for any
Taxes as above defined, such substituted taxes or assessments shall be included
in Taxes.

              (v) "Term" shall mean the term granted under the provisions hereof
as defined in Article 3.

                                ARTICLE 3 - TERM
                                ----------------

         SECTION 3.01 The Term ("Term") of this Lease shall begin on the
Commencement Date and end ONE-HUNDRED AND TWENTY (120), MONTHS FROM COMMENCEMENT
DATE.

         SECTION 3.02 Lessee shall have the right to renew this Lease for a
renewal term of five years commencing on the first day following the last day of
the Term of this Lease ("First Renewal Term") giving Lessor notice to such
effect not later than one year before the commencement of such Renewal Term,
provided that the Lease is in full force and effect and Lessee is not in default
thereunder both at the time of the giving of such notice and as of the
commencement of the Renewal Term. Upon the giving of such notice


                                      -3-
<PAGE>


under such circumstances, the Lease shall be automatically extended for the
Renewal Term referred to in such notice with the same effect as if such Renewal
Term had originally been included in the term of the Lease, and all of the
terms, covenants and conditions of the Lease, except such as are inapplicable or
inappropriate to such Renewal Term shall continue in fall force and effect for
such Renewal Term. All reference in the Lease to the Term of the Lease and to
the Termination Date shall be deemed to mean, when a Renewal term is in effect,
such Renewal Term and the date of expiration of such Renewal Term respectively.

                              ARTICLE 4 - BASE RENT
                              ---------------------

         SECTION 4.01 Lessee covenants and agrees to pay Lessor in lawful
currency of the United States in advance of or on the first day of each month
during the term without any previous demand therefore and without any setoff or
deduction, the following base rent ("Base Rent")as indicated in the rent
schedule on the following pages:


RENT SCHEDULE:
-------------

<TABLE>
<CAPTION>

                                                                                  Annual                Monthly
MONTHS 1-12                                  RSF                 Rate               Rent                  Rent
-------------------------------------------------------------------------------------------------------------------
<S>                                          <C>                 <C>               <C>                   <C>
Original Contract                            11,982              $14.00            $167,748.00           $13,979.00
Add.  Office: 3rd/ 4th Floor                  4,071              $15.00            $ 61,065.00           $ 5,088.75
Add.  Office: 1st Floor                       1,436              $15.00            $ 21,540.00           $ 1,795.00
                                                                                                         ----------
                                                                                                         $20,862.75
</TABLE>


<TABLE>
<CAPTION>

                                                                                  Annual                Monthly
MONTHS 13-24                                 RSF                 Rate               Rent                  Rent
-------------------------------------------------------------------------------------------------------------------
<S>                                          <C>                 <C>               <C>                   <C>
Original Contract                            11,982              $14.00            $167,748.00           $13,979.00
Add.  Office: 3rd/ 4th Floor                  4,071              $16.00            $ 65,136.00           $ 5,428.00
Add.  Office: 1st Floor                       1,436              $16.00            $ 22,976.00           $ 1,914.67
                                                                                                         ----------
                                                                                                         $21,321.67
</TABLE>


<TABLE>
<CAPTION>

                                                                                  Annual                Monthly
MONTHS 25-36                                 RSF                 Rate               Rent                  Rent
-------------------------------------------------------------------------------------------------------------------
<S>                                          <C>                 <C>               <C>                   <C>
Original Contract                            11,982              $14.00            $167,748.00           $13,079.00
Add.  Office: 3rd/ 4th Floor                  4,071              $17.00            $ 69,207.00           $ 5,767.25
Add.  Office: 1st Floor                       1,436              $17.00            $ 24,412.00           $ 2,034.33
                                                                                                         ----------
                                                                                                         $21,780.58
</TABLE>



                                      -4-
<PAGE>



<TABLE>
<CAPTION>

                                                                                  Annual                Monthly
MONTHS 37-48                                 RSF                 Rate               Rent                  Rent
-------------------------------------------------------------------------------------------------------------------
<S>                                          <C>                 <C>               <C>                   <C>
Original Contract                            11,982              $14.00            $167,748.00           $13,979.00
Add.  Office: 3rd/ 4th Floor                  4,071              $18.00            $ 73,278.00           $ 6,106.50
Add.  Office: 1st Floor                       1,436              $18.00            $ 25,848.00           $ 2,154.00
                                                                                                         ----------
                                                                                                         $22,239.50
</TABLE>


<TABLE>
<CAPTION>

                                                                                  Annual                Monthly
MONTHS 49-60                                 RSF                 RATE               RENT                  RENT
-------------------------------------------------------------------------------------------------------------------
<S>                                          <C>                 <C>               <C>                   <C>
Original Contract                            11,982              $14.00            $167,748.00           $13,979.00
Add.  Office: 3rd/ 4th Floor                  4,071              $19.00            $ 77,349.00           $ 6,445.75
Add.  Office: 1st Floor                       1,436              $19.00            $ 27,284.00           $ 2,273.67
                                                                                                         ----------
                                                                                                         $22,698.42
</TABLE>


<TABLE>
<CAPTION>

                                                                                  Annual                Monthly
MONTHS 61-120                                RSF                 Rate               Rent                  Rent
-------------------------------------------------------------------------------------------------------------------
<S>                                          <C>                 <C>               <C>                   <C>
Original Contract                            11,982              $14.00            $167,748.00           $13,979.00
Add.  Office: 3rd/4th Floor                   4,071         *TO BE NEGOTIATED
Add.  Office: 1st Floor                      1,436*         *TO BE NEGOTIATED                      ----------------
                                                                                                   TO BE DETERMINED
</TABLE>


*In no event will the rate be lower than $18.00 per rentable square foot.

         Lessee shall provide a security deposit of $20, 862.75.


         SECTION 4.02 The Annual Base Rental and all pertinent lease provisions
for the FIVE, (5) YEAR RENEWAL TERM shall be negotiated and the Annual Base
Rental shall be the then prevailing rental rate for reasonably comparable office
space in the building. However, in no event will the rental be less than the
Annual Base Rental of the last year.

             ARTICLE 5 - OPERATING EXPENSES. TAXES AND OTHER CHARGES
             -------------------------------------------------------

         SECTION 5.01 The base year tax will be determined by dividing, the
taxes, (as defined in Section 2.01(u)), assessed against Building and Parcel B
of the Spectra Plan of Lots for 1995, by the total square footage of the
rentable area of the Building, ("Base Year Tax").

         SECTION 5.02 In the event the taxes, (as defined in the Lease
Agreement), should exceed BASE YEAR TAX per square feet of Rentable Area of
Building, Tenant shall pay 55.11 % of the excess as additional rent.


                                      -5-
<PAGE>


         SECTION 5.03 Lessee shall pay Lessee's Share of Office Expenses and
Lessee's Share of Taxes as follows:

              (a) Lessee shall pay Lessor, monthly in advance, one-twelfth
(1/12th) of the amounts, if any, estimated from time to time by Lessor, to be
Lessee's Share of Office Expenses and Lessee's Share of Taxes.

(b) On or before May 30 of each Lease Year after the Term of this Lease
commences, Lessor shall furnish to Lessee a statement of the Office Expenses and
Taxes for the preceding Lease Year. To the extent that the Lessee's Share of
Office Expenses and/or Lessee's Share of Taxes for any Lease year or Partial
Lease Year is more than the amount actually paid by Lessee under subparagraph
(a), then Lessee shall pay the actual amounts of Office Expenses and/or Taxes
due Lessor within fifteen (15) days after receipt of the aforesaid statements.
If Lessee's share of Office Expenses and Taxes paid by Lessee for any Lease Year
or Partial Lease Year exceeds Lessee's Share of Office Expenses and/or Lessee's
Share of Taxes actually owed to Lessor, such excess shall be credited against
the amount next due from Lessee to Lessor pursuant to this Article.

         SECTION 5.04 Lessee further agrees to pay to Lessor the following
amounts:

              (a) Any and all sums which may become due by reason of the failure
of Lessee to comply with any one or more of the covenants of this Lease and any
and all damages, costs and expenses which Lessor may suffer or incur by reason
of any default of Lessee or failure on its part to comply with any one or more
of the covenants of this Lease, or any damages to the Premises caused by any act
or neglect of Lessee.

              (b) On any Rent which is not paid within ten (10)-days after the
due date, Lessee shall pay to Lessor, as a Late Rental Charge, interest at the
Default Rate. Said Late Rental Charge shall run from its, due date until such
Rent is received by Lessor.

              (c) All taxes becoming a lien or charge against the land and
Building to the extent that the same are assessed on the basis of the value of
any machinery or equipment installed by Lessee.

              (d) If there is a metered water connection to the Premises, all
charges for water consumed upon the Premises and all charges for repairs to the
meter or meters on the Premises, whether such repairs are made necessary by
ordinary wear and tear, freezing or hot water.

         SECTION 5.05 Any sums required to be paid by Lessee under this Lease
(other than Base Rent), including without limitation any sums payable under this
Article or Article 11, shall be deemed to be "Additional Rent". Lessee agrees to
pay (on demand unless otherwise specified) Additional Rent in lawful currency of
the United States without setoff or deduction whatsoever. Lessee's obligation to
pay any and all Additional Rent under this Lease shall survive any expiration or
termination of this Lease.

                                 ARTICLE 6 - USE
                                 ---------------

         SECTION 6.01 The Premises may be used and occupied for GENERAL OFFICE
PURPOSES, LIGHT ASSEMBLY, and no other purposes.


                                      -6-
<PAGE>


                     ARTICLE 7 - PRIOR OCCUPANCY, POSSESSION
                     ----------------------------------------

         Section 7.01 If Lessor shall be unable to give Lessee possession of the
Premises on or before one (1) year after Lease execution:

              (a) Lessor shall not thereby be liable in damages or otherwise to
Lessee; however, Lessee may elect to terminate the Lease upon thirty (30) days
written certified notice to Lessor. However, Lessor will have those thirty (3)
days to complete Premises, and if Lessor completes Premises within those thirty
(30) days, the Lease remains in full force and effect.

              (b) If not terminated, the Term shall be extended by the number of
days Lessee's possession is so delayed plus the number of days needed to cause
the Term to end on the last day of a calendar month.

              (c) If not terminated, rent shall be postponed on a daily rate
basis until possession shall be given.


                ARTICLE 8 - TERMINATION, EXTENSION AND HOLD-OVER
                -------------------------------------------------

         Section 8.01 Provided that Lessee has not renewed the Lease pursuant to
Section 3.02, this Lease shall terminate at the end of the Term, as defined in
Article 3, without the necessity of any notice from either Lessor or Lessee to
terminate the same. LESSEE HEREBY EXPRESSLY WAIVES NOTICE TO VACATE THE PREMISES
(INCLUDING, WITHOUT LIMITATION, ANY NOTICE PROVIDED FOR UNDER THE PENNSYLVANIA
LANDLORD AND TENANT ACT OF 1951, AS AMENDED 68 PA. C.S.A. 250.101 ET SEQ.) AND
AGREES THAT LESSOR SHALL BE ENTITLED TO THE BENEFIT OF ALL PROVISIONS OF LAW
RESPECTING THE SUMMARY RECOVERY OF POSSESSION OF THE PREMISES FROM A TENANT
HOLDING OVER TO THE SAME-EXTENT AS IF STATUTORY NOTICE HAD BEEN GIVEN.

         SECTION 8.02 In the event that the Premises are not surrendered at the
end of the Term, Lessee shall:

              (a) Indemnify Lessor against loss, liability and expenses
resulting from Lessee's delay in surrendering the Premises; and

              (b) Pay to Lessor one and one half times the Rent together with
all other sums payable hereunder then applicable for each month or portion
thereof that such delay exists.

The provisions of this Section shall not operate as a waiver by Lessor of any
remedies herein provided or to extend the Term.


                         ARTICLE - 9 - PLACE OF PAYMENT
                         ------------------------------

         SECTION 9.01 All Rent shall be payable to Lessor or its agents without
prior written notice or demand to Spectra Office Building ("Building") located
on 2953 Wexford-Bayne Road, Franklin Park Borough, Sewickley, Pennsylvania
15143, or any such other address as designated by Lessor in writing to Lessee.


                                      -7-
<PAGE>


                        ARTICLE 10 - LESSEE'S COVENANTS
                        -------------------------------

         SECTION 10.01 Lessee shall promptly fulfill and comply with all laws,
ordinances, regulations and requirements of the City, County, State and Federal
Governments and any and all departments thereof having jurisdiction over the
Building, relating to Lessee's occupancy of the Premises or the business
conducted therein.

         SECTION 10.02 Lessee shall use every reasonable precaution against fire
and notify Lessor of any condition which may have a negative impact on fire
security or safety.

         SECTION 10.03 Lessee shall give to Lessor prompt written notice of any
serious accident, fire, or damage occurring on or to the Premises.

         SECTION 10.04 Lessee shall attorn to and recognize as Lessor under the
Lease any transferee of Lessee's interest whether by voluntary or involuntary
sale or transfer, including but not limited to, any purchaser which shall
succeed to the interest of Lessor hereunder at any foreclosure sale or at any
sale under a power of sale contained in any mortgage that now exists or may
hereafter be placed upon the Land and Building or any part thereof and all
renewals, replacements, modifications, consolidations and extensions thereof as
the case may be, for the balance then remaining of the Term. Lessee shall
execute and deliver in recordable form whatever instruments may be required to
acknowledge such agreement to attorn.

         SECTION 10.05 Lessee shall not place or allow to be placed any stand,
booth, sign, or showcase or device or projection of any kind upon the doorsteps,
vestibules or outside walls, pavements or windows of the Premises or building
without the prior written consent of Lessor.

         SECTION 10.06 Lessee shall not make any alterations, improvements, or
additions to the Premises without the prior written approval of Lessor, which
approval shall not be unreasonably withheld. All alterations, improvements,
additions or fixtures, except that which is not considered normal office,
whether installed before or after the signing of the Lease, shall remain upon
the Premises at the expiration or sooner termination of this Lease and shall
become the property of Lessor.

         SECTION 10.07 Lessee shall not use or operate any machinery in office
area that, in Lessor's opinion, is harmful to the Building or disturbing to
other tenants occupying other parts thereof. It is also understood that all
other tenants have similar restrictions in office areas.

         SECTION 10.08 Lessee shall not place any weights in any portion of the
Premises beyond its safe carrying capacity.

                       ARTICLE 11 - SERVICES AND EQUIPMENT
                       -----------------------------------

         SECTION 11.01 Lessor shall initially install the Building's standard
HVAC system to serve the entire Premises.

         So long as Lessee is not in default under any of the covenants of this
Lease, Lessor shall subject to the provisions of Article 17 hereof provide
heating, ventilating and air-conditioning throughout the Premises


                                      -8-
<PAGE>



during Normal Business Hours and during normal heating and cooling seasons,
provided the Building standard occupancy conditions are not exceeded in any
partitioned area or subdivision of the Premises.

         SECTION 11.02 Lessee understands that after the Commencement Date, any
occupancy of the Premises above the Building standard occupancy conditions, or
any rearrangement of partitioning which interferes with normal operation of the
HVAC system may require changes or alterations in said systems, or in the ducts
through which the same operates, and Lessee accordingly agrees that any changes
or alterations so occasioned shall be made only with the prior written consent
of Lessor and shall be done by Lessor, at Lessee's expense, and in accordance
with the plans and specifications of Lessee to be submitted to and approved in
writing by Lessor.

         Whenever heat-generating machines or equipment installed by Lessee
affect the air-conditioning systems or the population or electrical load exceeds
the Building standard occupancy conditions, Lessor's responsibility for
providing heating, ventilating and air-conditioning shall be reduced
accordingly. Lessor reserves the right to install at Lessee's expense
supplementary air-conditioning equipment and equipment auxiliary to such
supplementary air-conditioning equipment in the Premises, and the charge for
such installation or operation shall be paid by Lessee to Lessor within ten (10)
days of being billed therefor.

         SECTION 11.03 Should Lessee require heating, ventilating, or
air-conditioning service on days or hours other than Normal Business Hours,
Lessor shall, upon reasonable advance notice by Lessee, furnish such additional
service and Lessee agrees to pay Lessor for such service within ten (10) days of
being billed therefor. Lessee will pay for additional service at a rate of $
10.00 per hour.

         SECTION 11.04 Lessor shall provide passenger elevator service (which
may be automatic, at Lessor's option) in common with others during Normal
Business Hours and have an elevator servicing the Premises subject to call at
any other times.

         SECTION 11.05 Lessor shall provide hot and unheated water for lavatory,
toilet and ordinary cleaning purposes and cold water for drinking purposes drawn
through facilities installed by Lessor. If Lessee requires, uses or consumes
water for any other purposes, Lessee agrees to the installation of a meter or
meters to measure Lessees domestic water consumption and Lessee further agrees
to pay Lessor, within ten (10) days of being billed therefor, for the meter or
meters and the installation thereto for the maintenance of said meter equipment
and for the water consumed. The charge for all excess water consumed as measured
by said meter or meters and sewage charges applicable to such water consumption
shall be paid within ten (M) days of being billed therefore.

         SECTION 11.06 Lessor shall maintain and keep clean the plaza, plaza
lobby, upper lobby, truck dock, public corridors and other public portions of
the Building.

         SECTION 11.07 Lessee shall pay Lessor, within ten (10) days of being
billed therefor, for the removal from the Premises and the Building of such
refuse and rubbish of Lessee as shall exceed that ordinarily accumulated daily
in the usual and customary business office.

         SECTION 11.08 Lessor shall provide standard cleaning and janitorial
services in and about the Building and the Premises (Saturdays, Sundays and
Holidays excepted), excluding office areas, in accordance with services normally
found 'in first class office buildings in the City of Pittsburgh, Pennsylvania.


                                      -9-
<PAGE>


         SECTION 11.09 Notwithstanding anything to the contrary in this Article
11 or in this Lease contained, Lessor may institute such policies, programs and
measure as may be necessary, required or expedient for the conservation and/or
preservation of energy or energy services, or as may be necessary to comply with
applicable laws, codes, rules or regulations.

                            ARTICLE 12 - ELECTRICITY
                            ------------------------

         SECTION 12.01 Electric current shall be supplied by Lessor to Lessee as
herein provided. The Base Rent includes a charge for consumption of electricity
for the Building standard 277-volt lighting fixtures installed in the Premises
and for normal small office machines and fixtures connected to the Building
standard 110-volt, single phase outlets during Normal Business Hours within
reason. Lessee shall pay monthly to Lessor, as Additional Rent for the
consumption of electricity used in the Premises for a total connected load in
excess of a total of 5 watts per square foot of Rentable Area of Lessee on any
floor occupied by Lessee at a rate computed on Lessor's average cost per
kilowatt hour. Such average cost shall be determined by dividing the total
kilowatt hours used in the Building into the total cost of the utility company's
electricity invoices for the Building. The amount of electrical consumption in
the Premises for a total connected load in excess of 5 watts shall be determined
by Lessor's reasonable estimate, or if requested by Lessee, by an engineering
analysis and/or study by a consultant retained by Lessor, such study to be at
Lessor's sole cost for computer floors and other special installations.
Additional electrical usage shall be determined by measurement of electric
meters to be installed as required by Lessor at Lessor's sole cost.

         Charges for excess or overtime electrical consumption shall be billed
and paid as Additional Rent.

         SECTION 12.02 Lessee agrees to pay Lessor, within ten (10) days of
being billed therefore, for all replacement lamps, bulbs, used in the Premises,
including the charge for installation thereto such payments to be deemed to be
and be paid as Additional Rent.

         SECTION 12.03  N/A

         SECTION 12.04 Lessee covenants and agrees that at all times its use of
electric current shall not exceed Lessee's proportionate share of the capacity
of existing feeders to the Building or the risers or wiring installation. Any
riser or risers or wiring to meet Lessee's excess electrical requirements, upon
written request of Lessee, will be installed by Lessor, at the sole cost and
expense of Lessee if, in Lessor's sole judgment, the same are necessary and will
not cause permanent damage or injury to the Building or Premises or cause or
create a dangerous or hazardous condition or entail excessive or unreasonable
alterations, repairs or expense or interfere with or disturb other tenants or
occupants.

         SECTION 12.05 Lessee shall make no alteration or additions to the
electric equipment or installation without the prior written consent of Lessor
in each instance and all work shall be done by Lessee at Lessee's expense in
accordance with plans and specifications of Lessee to be submitted and approved
by Lessor. All work to be performed by a registered electrician under full
compliance with all local and state codes.


                                      -10-
<PAGE>


         SECTION 12.06 At anytime when Lessor is furnishing electric current to
the Premises pursuant to this Article 12, it becomes illegal for Lessor to
continue to do so, Lessor may, upon not less than thirty (30) days' prior
written notice to Lessee, discontinue the furnishing of such electric current.
If Lessor gives any such notice of discontinuance, Lessor shall make all the
necessary arrangements with a public utility to furnish such electric current to
the Premises, but Lessee will contract directly with such public utility for the
supplying of such electric current to the Premises. If Lessor is unable to
provide adequate electric current for Lessee, Lessee will have the right to
terminate the said Lease immediately upon receiving such notice, provided the
demand does not exceed 5 watts per square foot.

                     ARTICLE 13 - LESSORS AND LESSEE'S WORK
                     ---------------------------------------

         SECTION 13.01 Within the Premises, Lessor shall provide at Lessor's
expense the items of construction, facilities and equipment shown or described
in the plans and specifications referred to in the Work Letter attached hereto
as Exhibit-D and specified to be "Lessor's Work". All Lessor's Work shall be
done at Lessor's expense and shall be performed by Lessor or by contractors
selected by Lessor.

         All work in the Premises other than Lessor's Work shall be performed by
Lessor or by contractors selected by Lessor but shall be paid by Lessee (herein
referred to as "Lessee's Work"). Lessee shall pay the actual cost of Lessee's
Work plus fifteen percent (15%) of such cost to Lessor for Lessor's overhead and
construction administration.

         SECTION 13.02 Lessee agrees to inspect the Premises prior to the
occupancy hereof before accepting the Premises (subject to Lessor's obligation
to complete Lessor's Work) in an "as is" condition. Except as specified herein,
Lessor has made no representation, either express or implied with respect to the
condition of the Premises. It is understood and agreed that Lessor is not under
any duty to make repairs or alterations at the time of letting or at any time
thereafter, except as otherwise provided herein.

                              ARTICLE 14 - REPAIRS
                              --------------------

         SECTION 14.01 Lessee shall keep the Premises and the fixtures and
appurtenances therein in good order and condition at its sole cost and expense
and shall make all repairs thereto caused by the negligence, misfeasance or
malfeasance of Lessee, its employees, guests, contractors and invitees, or by
its use of the Premises, or any part thereto in a manner not customary for the
purposes permitted hereunder, or which are not Lessor's obligations pursuant to
any provisions of this Lease, and shall commit no waste in the Premises or the
Building.

         SECTION 14.02 Lessor shall make all repairs necessary to maintain the
plumbing, heating, air conditioning and electrical systems, windows, floors,
roof and structure, and all other items which were installed or furnished by
Lessor, except repairs of

              (a) such installations which Lessee was obligated to make;

              (b) such installations made at Lessee's request; and


                                      -11-
<PAGE>


              (c) trade fixtures and other property belonging to Lessee.

However, Lessor shall not be obligated for any of such repairs until the
expiration of a reasonable period of time after receipt of written notice from
Lessee that such repairs are needed, unless such repairs are needed in common
areas of the building, in which case Lessor's obligation to repair without need
for notice from Lessee. In no event shall Lessor be obligated under this Article
to repair any damage caused by any act, omission or negligence of the Lessee or
its employees, agents, invitees, licensees, subtenants, contractors,
subcontractors or assignees.

         SECTION 14.03 All repairs, restorations or replacements by either party
shall be of first class quality and done in a good and workmanlike manner.

         There shall be no allowance to Lessee or diminution of Rent and no
liability on the part of Lessor by reason of inconvenience, annoyance or injury
to business arising from the making of any repairs, alterations, additions,
substitutions or improvements in or to any portion of the Building or the
Premises or in and to the fixtures, appurtenances and equipment thereof provided
that in each case such repairs, alterations, additions, substitutions or
improvements are effected in a manner which does not cause unreasonable
inconvenience to Lessee and provided further that in each case all work done in
connection with such repairs, alterations, additions, substitutions or
improvements is done promptly in a good and workmanlike manner. This provision
shall not be construed as to require Lessor to pay overtime but Lessee shall pay
the excess of the overtime cost over ordinary rates.

                       ARTICLE 15 - INSURANCE REQUIREMENTS
                       -----------------------------------

         SECTION 15.01 Lessee shall not do or permit to be done any act or thing
upon the Premises which will invalidate or be in conflict with the Certificate
of Occupancy for the Premises or the terms of any standard form of fire
insurance policies covering the Building and the fixtures and property therein;
and shall, at its own expense, comply with all rules, orders, regulations or
requirements of the National Fire Protection Association and the Insurance
Service Office of Pennsylvania or any other similar body having jurisdiction,
and shall not knowingly do or permit anything to be done in or upon the Premises
or bring or keep anything therein or use the Premises in a manner which
increases the rate of fire insurance upon the Building or on the property or
equipment located therein. Lessor certifies that certificate of occupancy
permits light assembly.

SECTION 15.02 If any installation in or use of the Premises by Lessee increases
the rate of fire insurance (with extended coverage) on the Building or on the
property and equipment of Lessor or any other tenant or subtenant in the
Building and such rate shall be higher than it otherwise would be, Lessee shall
reimburse Lessor for that part of the fire insurance premiums thereafter paid by
Lessor which shall have been charged because of such installation or use by
Lessee and Lessee shall make the reimbursement on the first day of the month
following such payment by Lessor and such reimbursement shall be deemed
Additional Rent.

         SECTION 15.03 Lessee covenants and agrees to provide on or before the
commencement of the Term and to keep in force during the entire term of this
Lease: (1) comprehensive general liability insurance for the mutual benefit of
Lessor and Lessee relating to the Premises and its appurtenances in an amount of
not


                                      -12-
<PAGE>


less than One Million Dollars ($1,000,000.00) in respect of personal injury or
death and of not less than One Hundred Thousand Dollars ($100,000.00) in respect
of property damage, which insurance shall name Lessor as an additional insured;
and (2) fire and extended coverage, vandalism, malicious mischief and special
extended coverage insurance in an amount adequate to cover the cost of
replacement of all leasehold or building improvements in the Premises which were
originally constructed or provided by or on behalf of Lessee as well as the cost
of replacement of all fixtures, equipment, decoration, contents and personal
property therein. All such insurance shall name Lessor as an additional insured
and contain a stipulation that it is Lessor's primary insurance. Lessee agrees
to delivery to Lessor at least fifteen (15) days prior to the time such
insurance is first required to be carried by Lessee, and thereafter at least
fifteen (15) days prior the expiration of any such policy, either a duplicate
original or a certificate of insurance procured by Lessee evidencing compliance
with its obligations hereunder, together with evidence of payment therefor.

         All of the aforesaid insurance shall be written by one (1) or more
responsible insurance companies satisfactory to Lessor and shall contain
endorsements that: (i) such insurance may not be cancelled or amended with
respect to Lessor, except upon thirty (30) days written notice by registered
mail to Lessor from the insurer; and (ii) Lessee shall be solely responsible for
payment of premiums for such insurance. In the event Lessee fails to furnish
such insurance, the Lessor any obtain such insurance and the premiums shall be
paid by Lessee to the Lessor upon demand. The minimum limits of the aforesaid
insurance shall be subject to increase at the end of every three (3) years
during the Term if Lessor in the exercise of its reasonable judgment shall deem
it necessary for adequate protection.

         SECTION 15.04 Each insurance policy carried by Lessor or Lessee and
insuring all or any part of the Building, the Premises, including improvements,
alterations and changes in and to the Premises made by either of them and
Lessee's trade fixtures and contents therein, shall be written in a manner to
provide that the insurance company waives all right of recovery by way of
subrogation against Lessor or Lessee, as the case may be, in connection with any
loss or damage to the Premises, or to the Building, or to property or businesses
caused by any of the perils covered by fire and extended coverage, and business
interruption insurance, for which either party may be reimbursed as a result of
insurance coverage affecting any loss suffered by it; provided, however, that
the foregoing waives shall apply only to the extent of any recovery made by the
parties hereto under any policy of insurance now or hereafter issued. So long as
the policy or policies involved can be so written and maintained in effect,
neither Lessor nor Lessee shall be liable to the other for any such loss or
damage. In the event of inability on the part of either party to obtain such
provision in its policy or policies with the carrier with whom such insurance is
then carried, or such carrier's requiring payment of additional premium for such
provision, the party so affected shall give the other party written notice of
such inability or the increase in premium as the case may be. The party to whom
such notice is given shall have fifteen (15) days from the receipt thereof
within which: (1) in the case of such inability on the part of the other party
to procure from the aforesaid other party's insurance carrier in writing, at no
increase in premium over that paid theretofore by the party so affected, such
waiver of subrogation; (2) in the case of increased premium, to pay the other
party so affected the amount of such increase; or (3) to waive, in writing
within the time limit set forth herein, such requirement to obtain the aforesaid
waiver of subrogation. Should the party to whom such notice is given fail to
comply as aforesaid within the said fifteen (15) day period, each and every
provision in this Section in favor of such defaulting party shall be cancelled
and of no further force and effect.

                      ARTICLE 16 - OBSERVANCE OF RULES AND
                   REGULATIONS AND COVENANT OF QUIET ENJOYMENT
                   -------------------------------------------


                                      -13-
<PAGE>


         SECTION 16.01 Lessee shall observe faithfully and comply strictly with
the Rules and Regulations set forth in Exhibit E attached hereto and made a part
hereof Lessor shall have the right from time to time to make changes in and
additions to the Rules and Regulations. It is understood that these same rules
and regulations Will apply to all tenants, including Lessor, in a non
discriminating manner.

         Any failure by Lessor to enforce the Rules and Regulations now or
hereafter in effect, either against Lessee or any other tenant in the Building,
shall not constitute a waiver by Lessor of such Rules and Regulations.

         SECTION 16.02 Lessor covenants that upon Lessee's paying Base Rent and
Additional Rent and observing and performing all the terms, covenants and
conditions of this Lease on its part to be observed and performed, Lessee may
peaceably and quietly enjoy the Premises without any hindrance from Lessor
subject, nevertheless, to the terms and conditions of this Lease.

                        ARTICLE 17 - LIABILITY OF LESSOR,
                   INDEMNIFICATION, AND EXCUSE OF PERFORMANCE
                   ------------------------------------------

         SECTION 17.01 Lessor shall provide reasonable security measures and
shall use its best efforts to protect Lessee's personnel and property.

         Both parties recognize that they are unable to guarantee that their
employees, agents, contractors, invitee and licensees will be free from the
criminal, intentional, reckless or tortious acts or omissions of third parties
affecting each others employees, agents, contractors, invitee and licensees and
its or their property and agree that each shall not be liable for any losses
therefrom.

         SECTION 17.02 Lessor shall not be liable for any injury or damage to
persons or property resulting from fire, explosion, falling plaster, steam, gas,
electricity, electrical disturbance, water, rain or snow or leaks from any part
of the Building or from the pipes, appliances or plumbing works or from the root
street or sub-surface or from any other-place, or caused by dampness or by any
other cause of whatever nature, unless caused by or due to the negligence of
Lessor, its agents, servants or employees, and then only after (i) notice to
Lessor of the condition claimed to constitute negligence and (ii) the expiration
of a reasonable time after such notice has been received by Lessor without
Lessor having taken all reasonable and practicable means to cure or correct such
condition; and pending such cure or correction by Lessor, Lessee shall take all
reasonable prudent temporary measures and safeguards to prevent any injury, loss
or damage to persons or property. In no event shall Lessor be liable for any
loss, the risk of which is covered by Lessee's insurance; nor shall Lessor be
liable for any loss, the risk of which is covered by Lessees insurance; nor
shall Lessor or its agents be liable for any such damage caused by other tenants
or persons in the Building or caused by operations in construction of any
private, public, or quasi-public work; nor shall Lessor be liable for any latent
defect in the Premises or in the Building.

         Lessor shall not be liable in any event for loss of, or damage to, any
property, entrusted to any of Lessor's employees or agents by Lessee without
Lessor's specific written consent.

         SECTION 17.03 Lessor shall not be liable to Lessee, its employees,
agents, contractors, invitee and licensees, and Lessee shall indemnify Lessor
and hold it harmless from and against any claims and any and all liability
arising from or occasioned by the injury or death of the employees, agents,
contractors, invitee and licensees of Lessee, irrespective of the cause of such
injury or death, unless solely caused by or due to


                                      -14-
<PAGE>


willful negligent acts or omissions of Lessor, its agents or employees acting
within the scope of their employment. Same shall apply to the Lessee.

         SECTION 17.04 Lessee shall defend, indemnify and save harmless Lessor
and its agents and employees against and from all liabilities, obligations,
damages, penalties, claims, costs, charges and expenses, including reasonable
attorneys fees, which may be imposed upon or incurred by or asserted against
Lessor and/or its agents during the Term of this Lease, or during any period of
time that Lessee may have been given access to or possession of all or any part
of the Premises arising directly or indirectly from any act or omission of
Lessee or any of Lessee's agents, employees, servants, licensees, contractors or
subleases. Same shall apply to the Lessor.

         In case any action or proceeding is brought against Lessor by reason of
any such claim, Lessee, upon written notice from Lessor, shall at Lessee's
expense resist or defend such action or proceeding by counsel approved by Lessor
in writing, which approval Lessor shall not unreasonably withhold or delay.
Lessee shall not enter into any settlement, offset, covenant not to sue, or
otherwise settle any action or proceeding without Lessor's permission, which
shall not be unreasonably withheld. Same shall apply to the Lessor.

         SECTION 17.05 Except where a utility is unavailable due to Lessor's
failure to pay utility bills in a timely manner, Lessor shall incur no liability
to Lessee whatsoever should any utility become unavailable from any public
utility company, public authority or any other person, firm or corporation,
including Lessor, supplying or distributing such utility. Except where a utility
is unavailable due to Lessor's failure to pay utility bills in a timely manner,
Lessor shall under no circumstances be liable to lessee in damages or otherwise
for any interruption in providing any utility service for any reason including
but not limited to breakdowns, making of repairs or improvements thereto and the
same shall not constitute a termination of this Lease or a constructive
eviction.

         SECTION 17.06 This Lease and the obligations of Lessee to pay Rent
hereunder and perform all of the other covenants, agreements, terms provisions
and conditions hereunder shall in no way be affected, impaired or excused
because Lessor is unable to fulfill or is delayed in fulfilling any of its
obligations under this Lease, prevented or delayed from by reason of any cause
whatsoever beyond Lessor's reasonable control, including, but not limited to,
accidents, acts of God, strikes, labor troubles, governmental preemption in
connection with a national emergency or by reason of any rule, order or
regulation of any department or subdivision thereof or of any governmental
agency or by reason of the conditions of supply and demand which have been or
are affected by war, hostilities or other similar emergency. Same shall apply to
the Lessor.

         SECTION 17.07 If at any time windows of the Premises or entrances to
the building are temporarily closed off, darkened or blocked up for any reason
whatsoever, Lessor shall not be liable for any damage Lessee may thereby sustain
and Lessee shall not be entitled to any compensation therefore or to any
abatement of Rent or release from any of its obligations hereunder or be
considered thereby to have been evicted.

         SECTION 17.08 Lessor reserves the right to interrupt, curtail, stop, or
suspend the supply of any service with reasonable advance notice, including, but
not limited to, the furnishing of heating, elevator, escalator, air
conditioning, and cleaning services, and the operation of plumbing and electric
systems, for repairs, alterations, replacements, or improvements. If any of the
event described in the Section occur, Lessor shall in each instance exercise
reasonable, diligence to effect performance or restore service when and


                                      -15-
<PAGE>


as soon as possible. If service cannot be restored within a 48 hour period
Lessee will receive a rental abatement for each day service continues to be
interrupted.

         SECTION 17.09 The provisions of this Article are intended to be
cumulative.

                   ARTICLE 18 - DAMAGE BY FIRE OR OTHER CAUSE
                   ------------------------------------------

         SECTION 18.01 If the Premises or the Building should be partially or
totally damaged or destroyed by fire or other cause, then (if this Lease shall
not have been cancelled as provided in this Section or Section 18.02) to the
extent Lessor recovers insurance proceeds, Lessor shall repair the damage, and
restore, replace, and rebuild the Building and Premises, to the condition
originally provided as Lessor's Work, with reasonable dispatch after notice to
it of the damage or destruction. Due allowance shall be made for any delay
resulting from labor strikes, acts of God or any other cause beyond Lessor's
reasonable control. Lessor shall not be required to repair or replace any
property which Lessee may be entitled to remove or which Lessor may be entitled
to require Lessee to remove from the Premises.

         If the Premises shall be partially damaged or partially destroyed, the
Rent payable hereunder shall be abated to the extent that the Premises shall
have been rendered untenantable or unfit for Lessee's use for the period from
the date of such damage or destruction to the date that the damage shall be
repaired or restored. If the Premises or a major part thereof shall be totally,
or substantially totally, damaged or destroyed or rendered completely or
substantially untenantable because of fire or other cause, the Rent shall abate
as of the date of the damage or destruction and until Lessor shall repair,
restore, replace and rebuild the Premises, provided, however, that should Lessee
reoccupy a portion of the Premises while the restoration work is taking place
and prior to the date the Premises are made completely tenantable, Rent shall be
apportioned and payable by lessee in proportion to the part of the Premises
occupied by it.

         Nevertheless, in case of such total or substantial damage to or
destruction of or complete, or substantial untenantability of the Premises,
Lessee may, at its option, cancel this Lease by written notice to Lessor, if
Lessor has not completed the making of the required repairs and restored,
replaced and rebuilt the Premises within eight (8) months from the date of such
damage or destruction.

         In the event the damage to the Premises or the Building should be so
extensive that Lessor shall decide not to repair or rebuild the Premises or the
Building, this Lease shall be terminated as of the date of such damage or
destruction by written notice from Lessor to Lessee, given within one hundred
twenty (120) days of such damage or destruction and Lessee shall thereupon
promptly vacate the Premises.

         SECTION 18.02 In case the Building or the Premises shall be
substantially destroyed by fire or other causes at any time during the last one
(1) year of the Term of this Lease either Lessor or Lessee may terminate this
Lease upon written notice to the other party hereto given within sixty (60) days
of the date of such destruction..

         SECTION 18.03 Unless this Lease is terminated as provided in this
Article, Lessee shall at its cost and expense repair, restore, replace and
rebuild the portion of the Premises constructed as Lessee's Work in a manner and
to at least a condition equal to that existing prior to such damage or
destruction. The proceeds of all insurance carried by Lessee with respect to
such portion of the Premises shall be delivered to Lessor and held in trust by
Lessor for the completion of Lessee's Work. All Lessee's work shall be performed
by Lessor or contractors selected by Lessor.


                                      -16-
<PAGE>


         SECTION 18.04 No damages, compensation or claim shall be payable by
Lessor for inconvenience, loss of business or annoyance arising from any repair
or restoration of any portion of the Premises or of the Building. Lessor shall
use its best efforts to effect such repairs promptly and in such manner as not
unreasonably to interfere with lessee's occupancy shall apply to both parties.

         SECTION 18.05 Lessor will not carry insurance of any kind on any
Lessee's Work or Lessee's furniture or furnishing or on any fixtures, equipment,
improvements or appurtenances of Lessee under this Lease.

                            ARTICLE 19 - CONDEMNATION
                            -------------------------

         SECTION 19.01 In the event that the whole or substantially the whole of
the Building shall be condemned or taken permanently for any public or
quasi-public use, this Lease, and the term and estate hereby granted, shall
forthwith cease and terminate as of the date of taking of possession for such
use or purpose.

         SECTION 19.02 In the event that less than the whole or substantially
the whole of the Building shall be so condemned or taken permanently or the
whole or substantially the whole of the Building condemned or taken temporarily,
this Lease shall remain in force and effect, except that (i) if the taking shall
nevertheless be so extensive that Lessor shall decide not to restore the
Building, then Lessor (whether or not the Premises are affected may at its
option terminate this Lease and the Term and estate hereby granted shall be
terminated as of the date of such taking of possession for such use, or (ii)
Lessee may if more than twenty-five percent (25%) of the Premises should be
condemned or taken and Lessee does not elect to accept relocation if offered,
Lessee in accordance with Section 19.03, elect at any time within thirty (30)
days of the date of such taking to cancel this Lease upon written notice to
Lessor, and thereupon this Lease shall terminate upon the date Lessee may
specify in said notice. Upon any such taking or condemnation and the continuing
in force of this Lease as to any part of the Premises, the Rent shall be abated
by an amount representing the part of the Rent properly allocable to the portion
of the Premises which may be so condemned or taken.

         SECTION 19.03 In the event that more than twenty-five percent (25%) of
the Premises is condemned or taken, Lessor may offer to relocate Lessee. Such
relocation shall be at Lessor's expense. Lessee shall not be required to accept
such offer.

         SECTION 19.04 In the event of the termination of this Lease pursuant to
the provisions of Section 19.01 and 19.02, this Lease and the Term and estate
hereby granted shall expire as of the date of such termination in the same
manner and with the same effect as if that were the date set for the normal
expiration of the Term of this Lease, and the Base Rent and any Additional Rent
shall be apportioned as of such date.

         SECTION 19.05 Lessor shall be entitled to receive the entire award
arising from any condemnation proceeding without deduction therefrom for any
estate vested in Lessee by this Lease and Lessee shall receive no part of such
award or awards, except as provided in Section 19.06. Lessee hereby expressly
assigns to Lessor any and all of its right, title and interest in or to such
award or awards or any part thereof.

         SECTION 19.06 Notwithstanding the foregoing, in the event of any
condemnation or taking pursuant to this Article, Lessee shall be entitled to
appear, claim, prove and receive in the condemnation proceeding such amounts as
may be separately awarded to Lessee for removal expenses, Lessee's fixtures,
equipment, work, or other improvements paid by Lessee, business dislocation,
damages and moving expenses, provided no such claims shall diminish or adversely
affect Landlord's award.


                                      -17-
<PAGE>

         SECTION 19.07 In the event of any condemnation or taking of less than
the whole of the Building, and this Lease shall continue in effect in whole or
in part, or in the event of a condemnation or taking for a temporary use or
occupancy of all or any part of the Premises, Lessor shall proceed with
reasonable diligence to repair, alter and restore the remaining part of the
Building and the Premises to substantially their former condition to the extent
that the same may be feasible and so as to constitute a complete and tenantable
Building and Premises; provided, however, nothing herein shall require Lessor to
spend any funds in excess of any award received by Lessor.

                               ARTICLE 20 - ENTRY
                               ------------------

         SECTION 20.01 Lessor or its agents or designees shall have the right to
enter the Premises, at reasonable times upon prior notice to Lessee's management
for the purpose of making such repairs or alterations as Lessor shall be
required or shall have the right to make by the provisions of this Lease or any
other lease in the Building.

         In the case of an emergency, Lessor shall have the right to enter the
Premises for reasonable purposes relating to the emergency.

         Lessor shall also have the right to enter the Premises, at reasonable
times upon prior written notice, for the purpose of inspecting it or exhibiting
it to prospective purchasers, lessees, or mortgagees, provided, however, Lessor
shall not unreasonably interfere with Lessee's use of the Premises.

                          ARTICLE 21 - RIGHT TO CHANGE
                          ----------------------------
                           PUBLIC PORTIONS OF BUILDING
                         ------------------------------

         SECTION 21.01 Lessor shall, upon written notice to Lessee, have the
right at any time after completion of the Building, without thereby creating an
actual or constructive eviction or incurring any liability to Lessee therefore,
to change the arrangement or location of such of the following as are not
contained within the Premises or any part thereof: entrances, passageways, doors
and doorways, corridors, stairs, toilets and other like public service portions
of the Building. Nevertheless, Lessor shall not make any change which shall
materially interfere with access to the Premises from and through the Building
or change the character of the Building from that of a first-class office
building.

         Lessor reserves the right, at it discretion and upon written notice to
Lessee, to change the name of the Building without creating or incurring any
liability to Lessee therefore, or interfere with the permitted use of the
premises.

                             ARTICLE 22 - BANKRUPTCY
                             -----------------------

         SECTION 22.01 If at any time prior to the Commencement Date or during
the Term of this Lease there shall be entered a decree or order providing for
relief by a court having jurisdiction in the Premises in respect of the Lessee
in an involuntary case under any applicable bankruptcy insolvency, or other
similar law now or hereafter in effect, or appointing a receiver, liquidator,
assignee, custodian, trustee sequestrator (or similar official) of the Lessee or
for any substantial part of its property, or ordering the winding-up or
liquidation of its affairs and if such decree or order shall continue unstayed
and in effect for a period of sixty (60) consecutive days, this Lease, at the
option of the Lessor exercised within a reasonable period of time after


                                      -18-
<PAGE>



notice of the happening of any such event, may be cancelled and terminated and
in such event neither Lessee nor any person claiming through or under Lessee or
by virtue of any statute or of any order of any court shall be entitled (i) in
the case of any such event happening prior to the Commencement Date, to
possession of the Premises, or (ii) in the case of any such event happening
during the Term of this Lease to remain in possession of the Premises and Lessee
shall forthwith quit and surrender the Premises and Lessor, in addition to the
other rights and remedies it has by virtue of any other provisions in this Lease
contained or by virtue of any statute or rule of law, may retain as liquidated
damages any Rent, security deposit or monies received by it from Lessee or
others in behalf of Lessee upon the execution of this Lease.

         SECTION 22.02 If at any time prior to the Commencement Date or during
the Term of this Lease there shall be commenced by the Lessee a voluntary case
under any applicable bankruptcy, insolvency or other similar law now or
hereafter in effect, or if the Lessee should consent to the entry of an order
for relief in an involuntary case under any such law, or if the Lessee should
consent to the appointment of or to the taking of possession of the Premises or
a substantial part of the Lessee's assets or property by a receiver, liquidator,
assignee, trustee, custodian, sequestrator (or other similar official), or if
the Lessee should make any assignment for the benefit of creditors, or if the
Lessee should fail generally to pay its debts as such debts become due (within
the meaning of the Bankruptcy Reform Act of 1978, as amended) or if the Lessee
takes any action in furtherance of any of the foregoing, this Lease at the
option of the Lessor exercised within a reasonable time after notice of the
happening of any one or more of such events, may be cancelled and terminated by
Lessor, in which event neither Lessee nor any person claiming through or under
Lessee by virtue of any statute or of any order of any court shall be entitled
(i) in the case of any such event happening prior to the Commencement Date, to
possession of the Premises, or (ii) in, the case of any such event happening
during the Term of this Lease to remain in possession of the Premises, and
Lessee shall forthwith quit and surrender the Premises and Lessor, in addition
to the other rights and remedies it has by virtue of any other provisions in
this Lease contained, or by virtue of any statute or rule of law, may retain as
liquidated damages any Rent, security deposit or moneys received by Lessor from
Lessee or others on behalf of Lessee.

         SECTION 22.03 It is stipulated and agreed that in the event of the
termination of the Lease pursuant to this Article or due to the failure of
Lessee to pay the Rent required to be paid by Lessee under the provision of this
Lease, Lessor shall forthwith, notwithstanding any other provisions of this
Lease to the contrary, be entitled to recover from Lessee as and for liquidated
damages an amount equal to the difference between the Rent reserved hereunder
for the unexpired portion of the Term of this Lease, and the rental value of the
Premises, if lower than the Rent reserved, at the time of termination, for the
unexpired portion of the Term of this Lease, both discounted at the rate of five
percent (5%) per annum to present worth subject to any limitation placed on such
recovery by the Bankruptcy Reform Act of 1978, as amended, or any other
successor statute; nothing herein contained shall limit or prejudice the right
of Lessor to prove for and obtain as liquidated damages by reason of such
termination an amount equal to the maximum amount allowed by any statute or rule
or law in effect at the time when, and governing the proceedings in which, such
damages are to be proved, whether or not such amount be greater than, equal to,
or less than the amount of the difference referred to above.

                    ARTICLE 23 - DEFAULTS: REMEDIES: DAMAGES
                    ----------------------------------------

         SECTION 23.01 Any one or more of the following events shall constitute
an "Event of Default":


                                      -19-
<PAGE>


              (a) The sale of Lessee's interest in the Premises under
attachment, execution or similar legal process.

              (b) The occurrence of any event referred to in Article 22 and, in
the case of an occurrence of any event referred to in Section 22.01, the
continuance of such event for the time period therein specified; then in any
such event Lessor at any time thereafter may give written notice to Lessee
specifying such Event of Default or Events of Default and stating that this
Lease and the Term of this Lease hereby demised shall expire and terminate on
the date specified in such notice, which shall be at least twenty (20) days
after the giving of such notice and upon the date specified in such notice this
Lease and the Term of this Lease and all rights of Lessee under this Lease,
including without limitation any renewal privileges, options for additional
space or other privileges, whether or not heretofore exercised, shall expire and
terminate, but Lessee shall remain liable as hereinafter provided.

              (c) The failure of Lessee to pay any Rent or other sum of money
within ten (10) days after the same is due hereunder.

(d) Failure by Lessee in the performance or observance of any covenant or
agreement of this Lease (other than failure involving the payment of money),
which failure is not cured within thirty (30) days after the giving of notice
thereof by Lessor, unless such failure is of such nature that it cannot be cured
within such thirty (30) day period, in which case Lessee shall not exercise the
remedies described below so long as Lessee shall commence the curing of the
default within such thirty (30) day period and shall thereafter diligently
prosecute the curing of same.

              (e) Lessee should default in performance of any other particular
covenant of this Lease more than six (6) times in any period of eighteen (18)
months, then, notwithstanding that such defaults shall have each been cured
within the period after notice as above provided, any further similar default
shall be deemed to be deliberate and Lessor thereafter may serve the said
written seven (7) day notice of termination. without affording to Lessee and
opportunity to cure such further default.

         SECTION 23.02 Upon the occurrence and continuance of an Event of
Default, Lessor, with advance written notice to Lessee in any instance (except
where expressly provided) may do any one or more of the following:

              (a) Declare all Rent, charges and any other sums due to Lessor by
Lessee to become accelerated and immediately due and payable.

              (b) Sell at public or private sale all or any part of the goods,
chattels, fixtures and other personal property belonging to Lessee which are or
may be put into the Premises during the Term, whether exempt or not from sale
under execution or attachment (it being agreed that said property shall at all
times be bound with a lien in favor of Lessor and shall be chargeable for all
Rent and for the fulfillment of the other covenants and agreements herein
contained) and apply the proceeds of such sale, first to the payment of all
costs and expenses of conducting the sale or caring for or storing said
property; second, toward the payment of any indebtedness, including (without
limitation) indebtedness for Rent, which may be or may become due from Lessee to
Lessor; and third, to pay to Lessee, on demand in writing, any surplus remaining
after all indebtedness of Lessee to Lessor has been fully paid.

              (c) Perform, on behalf and at the expense of Lessee, any
obligation of Lessee under this Lease which Lessee has failed to perform and of
which Lessor shall have given Lessee notice, the cost of


                                      -20-
<PAGE>


which performance by Lessor, together with interest thereon at the Default Rate
from the date of such expenditure until the date Lessor. receives reimbursement,
shall be deemed Additional Rent and shall be payable by Lessee to Lessor upon
demand.

              (d) Elect to terminate this Lease and the tenancy created hereby
by giving notice of such election to Lessee, and reenter the Premises, by
summary proceedings or otherwise, and remove Lessee and all other persons and
property from the Premises, and store such property in a public warehouse or
elsewhere at the cost of and for the account of Lessee without resort to legal
process and without Lessor being deemed guilty of trespass or becoming liable
for any loss or damage occasioned thereby.

              (e) Exercise any other legal or equitable right or remedy which it
may have.

         Notwithstanding the provisions of clause (c) above and regardless of
whether an Event of Default shall have occurred, Lessor may exercise the remedy
described in clause (c) without any notice to Lessee if Lessor, in its good
faith judgment, believes it would be materially injured by failure to take rapid
action or if the unperformed obligation of Lessee constitutes an emergency.

         SECTION 23.03 If the Lease is terminated pursuant to this Article,
Lessor may relet the Premises or any part thereof, alone or together with other
premises, for such term or terms (which may be greater or less than the period
which otherwise would have constituted the balance of the Term) and on such
terms and conditions (which may include concessions or free rent and alterations
of the Premises) as Lessor, in its uncontrolled discretion, may determine, but
Lessor shall not be liable for, nor shall Lessee's obligations hereunder be
diminished by reason of, any failure by Lessor to relet the Premises or any
failure of Lessor to collect any rent due upon such relenting. Any rental
collected by Lessor under a sublet must be considered as offset against any
rental due by Lessee.

         SECTION 23.04  N/A

         SECTION 23.05 Upon an Event of Default and in addition to any and all
remedies provided hereunder or by law, Lessee hereby empowers any attorney of
any court of record within the United States to appear for Lessee and, with or
without declaration filed, confess judgment against Lessee and in favor of
Lessor, or in favor of any other person to whom Lessee owes amounts under this
Lease, for the specific amount of Rent and any other additional charges due by
reasons of such default or breach, or for such costs of suit and attorney's
commission of the greater of ten percent (10%) of the amount due or One Thousand
Dollars ($1,000.00) for collection and forthwith issue a writ or writs or
execution thereon, with release of all errors, and without stay of execution,
and inquisition and extension upon any levy on real estate is hereby expressly
waived, and condemnation agreed to, and exemption of any and all property from
levy and sale by virtue of any exemption law now in force or which may be
hereafter enacted is also expressly waived by Lessee. Lessee further authorizes
and empowers any such attorney, either in addition to or without such judgment
for the specific amount of Rent or accelerated rents due under this Lease, to
appear for Lessee, and for any other persons claiming under, by or through
Lessee, and confess judgment forthwith against Lessee and such other persons and
in favor of Lessor, in an amicable action of ejectment for the Premises, with
all the conditions, fees, releases, waivers and confessions of judgments in
ejectment as are set forth in this Article for confession of judgment for
amounts due. The entry of judgment under the foregoing warrants shall not
exhaust the warrants, but successive judgments may be entered thereunder from
time to time as often as defaults occur.


                                      -21-
<PAGE>

         SECTION 23.06 Lessee expressly releases to Lessor and to any and all
attorneys who may appear for Lessee all errors in said proceedings, and all
liability therefor.

         SECTION 23.07 No reference to any specific right or remedy shall
preclude Lessor from exercising any other right or from having any other remedy
or from maintaining any action to which it may otherwise be entitled by law or
in equity. No failure by Lessor to insist upon the strict performance of any
agreement, term, covenant or condition hereof or to exercise any right or remedy
consequent upon a breach thereof, and no acceptance of full or partial rent
during the continuance of any such breach, shall constitute a waiver of any such
breach, agreement term, covenant or condition. No waiver by Lessor of any breach
by Lessee under this Lease or of any breach by any other tenant under any other
lease of any portion of the Building shall affect or alter this Lease in any way
whatsoever.

          ARTICLE 24 - ASSIGNMENT, MORTGAGING, SUBLEASING AND RECAPTURE
          -------------------------------------------------------------

         SECTION 24.01 Lessee shall not without Lessor's prior written consent,
not to be unreasonably withheld, assign this Lease or sublet all or any part of
the Leased Premises. However, Lessee may, without consent of Lessor, sublet or
assign to its parent or in connection with a consolidation or merger of Lessee
to the consolidated or merged company, provided they are credit worthy, but such
assignment or subletting shall not relieve Lessee of its obligations under this
Lease.

         SECTION 24.02 If Lessee desires to sublease all or any part of the
Premises or to assign its interest in this Lease Lessee shall, by notice
("Notice") in writing, advise Lessor of its intention from, on and after a
stated date (which shall not be less than sixty (60) days after the date of the
Notice), to sublease any part or all of the Premises or to assign its interest
in this Lease and in such event, Lessor shall have the right to be exercised by
giving written Notice to Lessee thirty (30) days after receipt of Lessee's
Notice, to recapture the space described in Lessee's Notice and such recapture
Notice shall if given cancel and terminate this Lease with respect to the space
therein described as of the date stated in Lessee's Notice. If the Lessee's
Notice shall cover all of the Premises, and if Lessor shall give the aforesaid
recapture Notice with respect thereto, the Term of this Lease shall expire and
end on the date stated in Lessee's Notice as fully and completely as if that
date had been herein definitely fixed for the expiration of the term of this
Lease. If, however, this Lease shall be cancelled pursuant to the foregoing with
respect to less than the entire Premises, the Base Rent and any Additional Rent
shall be adjusted on the basis of the number of square feet retained by Lessee
in proportion to the number of square feet contained in the Premises, as
described in this Lease, and this Lease as so amended shall continue thereafter
in full force and effect.

         A sublease permitted hereunder shall be subject to and made upon the
following terms:

              (1) Any such sublease shall be subject to the terms of this Lease
and the term thereof may not extend beyond the expiration or other termination
of the Term of this Lease and no sublease shall release or relieve Lessee of any
of its obligations hereunder;

              (2) The use to be made of the subleased space shall be permissible
under this Lease and in keeping with the character of the Building;

              (3) Such sublease shall not violate any negative use covenants
relating to the Building;

              (4) No sublease shall be valid and no subtenant shall take
possession of the Premises until an executed counterpart of such sublease has
been delivered to the Lessor;


                                      -22-
<PAGE>


              (5) No sublessee shall have a right to further sublease;

              (6) Rent for subleased space shall not be lower than the current
rate for comparable space in the Building during the last year of term.

              (7) Any Rents received by Lessee which are in excess of the Rents
payable under the Lease shall be payable fifty percent (50%) to Lessee and fifty
percent (50%) to the Lessor

              (8) Lessee shall not advertise the availability of the Premises
for subletting without Lessor's approval as to the form and content thereof, not
to be unreasonably withheld.

                           ARTICLE 25 - SUBORDINATION
                           --------------------------

         SECTION 25.01 This Lease and all the rights of Lessee hereunder are
subject and subordinate to the terms of any and all mortgages, ground leases,
superior leases and rents which do now or may hereafter affect the real property
of which the Premises from a part and to any and all renewals, modifications,
consolidations, replacements and extensions thereof. It is the intention of the
parties that this provision be self-operative in that no further instrument
shall be required to effect such subordination of this Lease. Lessee shall,
however, upon demand at any time or times execute, acknowledge and deliver to
Lessor without expense to Lessor, any and all instruments that may be necessary
or proper to subordinate this Lease and all rights of Lessee hereunder to any
such mortgage or lease or to confirm or evidence such subordination. Lessee
hereby appoints the Lessor, and/or the holder of such mortgage or lease, the
attorney-in-fact, irrevocably, of Lessee to execute and deliver for and on
behalf of Lessee any such instrument.

         SECTION 25.02 Subordination of this Lease shall not disturb Lessee's
possession or terms and conditions under this Lease provided Lessee shall not
then be in default hereunder.

                        ARTICLE 26 - RIGHTS OF HOLDER OF
                        --------------------------------
                     MORTGAGE IN EVENT OF DEFAULT BY LESSOR
                     --------------------------------------

         SECTION 26.01 In the event of any act or omission by Lessor which would
give Lessee the right to terminate this Lease or to claim a partial or total
eviction, Lessee shall not exercise any such right (a) until it has notified in
writing the holder of any first mortgage lien on the Land and/or Building, if
the name and address of such holder shall previously have been furnished by
written notice to Lessee, of such act or omission, and (b) until reasonable
period for remedying such act or omission shall have elapsed following the
giving of such notice, provided such holder, with reasonable diligence, shall
have commenced and continued to remedy such act or omission or to cause the same
to be remedied.

         SECTION 26.02 In the event that prior to or during the Term, if any
proposed institutional holder of a first mortgage on the Building shall demand
that this Lease be modified or amended in any respect (except for those
provisions relating to the rental or other economic terms, lease term or size of
the premises), Lessee agrees to reasonably cooperate with Lessor and said
mortgagee will not unreasonably withhold its consent to such requested changes.

                       ARTICLE 27 - SURRENDER OF PREMISES
                       ----------------------------------


                                      -23-
<PAGE>


         SECTION 27.01 Upon the expiration or other termination of this Lease
for any cause whatsoever. Lessee shall remove Lessee's goods, effects, personal
property, business and trade fixtures, machinery and equipment and those of any
persons claiming under Lessee, and quit and deliver upon the Premises to Lessor
peaceably and quietly in as good order and condition as the same are at the
commencement of the Term of this Lease or may thereafter be improved by Lessor
or Lessee, reasonable use and wear thereof, fire, unavoidable casualty and
repairs which are Lessor's obligations excepted. Lessee's goods, effects,
personal property, business and trade fixtures, machinery and equipment not
removed by Lessee at the expiration or other termination of this Lease (or
commenced to be removed within forty-eight (48) hours after a termination by
reason of Lessee's default) shall be considered abandoned and Lessor may dispose
of the same as it deems expedient, but Lessee shall promptly reimburse Lessor
for any expenses incurred by Lessor in connection therewith, including without
limitation the cost of removal thereof and repairing any damage occasioned by
such removal.

         Lessee's obligation to observe or perform this covenant shall survive
the expiration or other termination of the Term of this Lease.*

                   ARTICLE 28 - EFFECT OF CONVEYANCE BY LESSOR
                   -------------------------------------------

         SECTION 28.01  N/A

                              ARTICLE 29 - NOTICES
                              --------------------

         SECTION 29.01 Any notice or demand required or permitted to be given by
the terms and provisions of this Lease, or by any law or governmental
regulations, either by Lessor to Lessee, or by Lessee to Lessor, shall be in
writing. Unless otherwise required by such law or regulation, such notice or
demand shall be given, and shall be deemed to have been given by Lessor and
received by Lessee, three (3) business days after the date on which Lessor shall
have deposited such notice or demand by registered or certified return receipt
requested mail with the U.S. Postal Service addressed to Lessee at the Premises
or the day upon which such notice or demand is hand delivered to an officer or
director of the Lessee at the Premises. Any such notice or demand shall be given
and shall be deemed to have been served and given by Lessee and received by
Lessor, three (3) business days after the date on which Lessee shall have
deposited such notice or demand by registered or certified mail in such a post
office addressed to Lessor at:

                  Spectra Development Company
                  2593 Wexford-Bayne Road
                  Sewickley, Pennsylvania 15143

         Either party may, by notice of aforesaid, designate a different address
or addresses for notices or demands to it.

         SECTION 29.02 However, notices requesting services during other than
Normal Business Hours pursuant to Article 11 may be given, either in writing to
the person in the Building designated by Lessor to receive such notices or
through Lessor's computerized answering service for such purposes.

                        ARTICLE 30 - WAIVER OF REDEMPTION
                        ---------------------------------

         SECTION 30.01  N/A



                                      -24-
<PAGE>


                        ARTICLE 31 - ESTOPPEL CERTIFICATE
                        ---------------------------------

         SECTION 3 1.01 Lessor and Lessee each agree at any time, and from time
to time, upon not less than fifteen (15) days' prior notice to execute,
acknowledge and deliver, without cost or expense, to the other party, a
statement in writing certifying that this Lease is unmodified and in full force
and effect (or if there have been modifications, that the same is in full force
and effect as modified and further stating the modifications) and the dates to
which the Base Rent, Additional Rent and other charges have been paid, and
stating whether or not to the best knowledge of the signer of such certificate,
the other party is in default in performance of any covenant agreement, term,
provision or condition contained in this Lease on its part to be performed, and,
if so, specifying each such default of which the signer may have knowledge, it
being intended that any such statement delivered pursuant hereto may be relied
upon by any other party with whom the party requesting such certificate may be
dealing.

                           ARTICLE 32 - MISCELLANEOUS
                           --------------------------

         SECTION 32.01 SUCCESSORS AND ASSIGNS. This Lease and the covenants and
conditions herein contained shall inure to the benefit of and be binding upon
Lessor, its permitted successors and assigns, and shall be binding upon Lessee,
its successors and assigns and shall, inure to the benefit of Lessee and its
permitted assigns.

         SECTION 32.02 CAPTIONS AND HEADINGS. The table of contents and the
Article and Section captions and headings are for convenience of reference only
and in no way shall be used to construe or modify the provisions set forth in
this Lease.

         SECTION 32.03 JOINT AND SEVERAL LIABILITY. If two or more individuals,
corporations, partnerships or other business associations (or any combination of
two or more thereof) shall sign this Lease as Lessee, the liability of each such
individual, corporation, partnership or other business association to pay rent
and perform all other obligations hereunder shall be deemed to be joint and
several, and all notices, payments and agreements given or made by, with or to
any one of such individuals, corporations, partnerships or other business
associations shall be deemed to have been given or made by, with or to all of
them in like manner. If Lessee shall be a partnership or other business
association, the members of which are, by virtue of statute or law, subject to
personal liability, the liability of each such member shall be joint and
several.

         SECTION 32.04 BROKER'S COMMISSION. Each of the parties represents and
warrants that, except for a commission that will be owed by Lessor to the
Gustine Company, there are no claims for brokerage commissions or finder's fees
in connection with the execution of this Lease, and agrees to indemnify the
other against, and hold it harmless from, all liability arising from any such
claim including, without limitation, the cost of counsel fees in connection
therewith.

         SECTION 32.05 NO DISCRIMINATION. It is intended that the Building shall
be operated so that all prospective tenants thereof, and all customers,
employees, licensees and invitees of all tenants shall have the opportunity to
obtain all the goods, services, accommodations, advantages, facilities and
privileges of the Building without discrimination because of race, creed, color,
sex, age, national origin or ancestry. To that end, Lessor or Lessee will not
discriminate in the conduct and operation of its business in the Premises
against any person or group of persons because of the race, creed, color, sex,
age, national origin or ancestry of such person or group of persons.


                                      -25-
<PAGE>

         SECTION 32.06 NO JOINT VENTURE. Any intention to create a joint venture
or partnership or any relationship other than Lessor and Lessee between the
parties hereto is hereby expressly disclaimed.

         SECTION 32.07 NO OPTION. The submission of the Lease for examination
does not constitute a reservation of or option for the Premises, and this Lease
shall become effective only upon execution and delivery thereof by both parties.

         SECTION 32.08 NO MODIFICATION. This writing is intended by the parties
as a full expression of their agreement and as a complete and exclusive
statement of the terms thereto all negotiations, considerations and
representations between the parties having been incorporated herein. No course
of prior dealings between the parties or their officers, employees, agents or
affiliates shall be relevant or admissible to supplement, explain, or vary any
of the terms of this Lease. Acceptance of, or acquiescence in, a course of
performance rendered under this or any prior agreement between the parties or
their affiliates shall not be relevant or admissible to determine the meaning of
any of the terms of this Lease. No representations, understandings, or
agreements have been made or relied upon in the making of this Lease other than
those specifically set forth herein. This Lease can be modified only by a
writing signed by the party against whom the modification is enforceable.

         SECTION 32.09 SEVERABILITY. If any term or provision, or any portion
thereof, of this Lease, or the application thereof to any person or
circumstances shall, to any extent be invalid or unenforceable, the remainder of
this Lease, or the application of such term or provision to persons or
circumstances other than those as to which it is held invalid or unenforceable,
shall not be affected thereby, and each term or provision of this Lease shall be
valid and be enforced to the fullest extent permitted by law.

         SECTION 32.10  LIMITED LIABILITY.  N/A

         SECTION 32.11 THIRD PARTY BENEFICIALLY. Nothing contained in this Lease
shall be construed so as to confer upon any other party the rights of a third
party beneficiary except rights contained herein for the benefit of a Mortgagee.

         SECTION 32.12 CORPORATE LESSEES. In the event Lessee is a corporation,
the persons executing this Lease on behalf of Lessee hereby covenant and warrant
that: Lessee is a duly constituted corporation qualified to do business in the
state in which the Premises are situate, and such persons are duly authorized by
the board of directors of such corporation to execute and deliver this Lease on
behalf of the corporation.

         SECTION 32.13 APPLICABLE LAW. This Lease and the rights and obligation
of the parties hereunder shall be construed in accordance with the laws of the
Commonwealth of Pennsylvania.

                             ARTICLE 33 - RELOCATION
                             -----------------------

         SECTION 33.01 Lessor shall have the option to relocate at Lessor's
expense the Premises at any time or times during the Term to a different
location in the Building (herein referred to as "the New Premises"). Lessor may
exercise such option by giving Lessee written notice thereof not less than
thirty (30) days prior to the proposed effective date of relocation. Lessor must
receive Lessee consent, not to be unreasonably withheld.

         SECTION 33.02 If Lessor exercises its option to relocate the Premises:



                                      -26-
<PAGE>


              (a) The New Premises shall contain at least the amount of the
Rentable Area contained in the Premises, but not more than Lessee is currently
paying.

              (b) Lessor shall pay the direct costs, including physical moving
expenses (including telephone and telephone equipment relocation costs) incurred
by Lessee in relocating from the Premises to the New Premises and for improving
the New Premises so that they are substantially similar, including skylight and
open atrium, to the Premises, but in no event shall Lessor pay any indirect
expenses incurred by Lessee in relocating from the Premises to the New Premises
(including salaries of employees of Lessee for time allocated to such
relocation, legal fees or loss of business profit). Window space must be at
least as great in the new premises as the old premises.

              (c) The Base Rent specified in Section 4.01 for the then current
Portion of the Term shall remain the same, or be decreased to the product
obtained by multiplying such Base Rent by a fraction, the numerator of which is
the Rentable Area contained in the New Premises and the denominator of which is
the Rentable Area contained in the Premises, and the Base Rent for any future
Portions of the Term shall remain the same, or be decreased if warranted, but no
increase in rentable area.

              (d) The Rentable Area of the premises specified in Section 1.02
shall be decreased, as the case may be, by the difference in the Rentable Area
contained in the Premises and the Rentable Area contained in the New Premises;

              (e) Lessee's Percentage of Office Expenses would not be
recalculated; and,

              (f) Lessee's Percentage of Taxes shall be recalculated in
accordance with the formula specified in Subsection 2.01 (k).


                                      -27-
<PAGE>


         IN WITNESS WHEREOF, the parties hereto have executed these presents the
day and year first above written.


WITNESS:                                SPECTRA DEVELOPMENT COMPANY


  /s/ Susan A. Majeski                  By:  /s/  Gary A. Sippel
----------------------------------         ------------------------------------


ATTEST:                                  NOMOS Corporation


                                         By:    /s/  [Illegible]
----------------------------------          -----------------------------------


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


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


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




                                      -28-
<PAGE>



                                   EXHIBIT "A"

                             Exhibit "A" Page 1 of 3

                            [FLOOR PLAN OF LEVEL ONE]

                                  ACCEPTED BY:

                      [Illegible]               DATE: 8/18/94


<PAGE>



                                   EXHIBIT "A"

                             Exhibit "A" Page 2 of 3

                           [FLOOR PLAN OF LEVEL THREE]

                                  ACCEPTED BY:
                      [Illegible]               DATE: 8/18/94


<PAGE>


                                   EXHIBIT "A"

                             Exhibit "A" Page 3 of 3

                           [FLOOR PLAN OF LEVEL FOUR]

                                  ACCEPTED BY:
                      [Illegible]               DATE: 8/18/94


<PAGE>


                                   EXHIBIT "B"

                                      [MAP]


<PAGE>


                                   EXHIBIT "C"
                                BUILDING SERVICES


         Subject to the provisions of Article 14 of the Lease, Lessor shall
provide, within its standards on each item, the following services and
facilities:

1. Electric current for building standard level of illumination using standard,
fixtures of Lessor's choice, and replacement of light globes and/or fluorescent
tubes in the standard lighting fixtures installed in the common areas by Lessor.
Standard electrical current shall be defined throughout the term of this Lease
as 208-120 volt, 100 amp service, single phase.

2. Maintenance of service of the public toilet rooms in the Building.

3. Maintenance of standard hardware installed in the Premises by Lessor.

4. Maintenance and sealing of ceramic tile floors.

5. Cleaning of exterior window panels.

6. Cleaning and maintenance of common areas in the Building

7. Hot and cold water for lavatory and drinking purposes. If Lessee requires
water for additional purposes, Lessee shall pay the cost thereof as shown on a
meter to be installed and maintained at Lessee's expenses to measure such
consumption.


<PAGE>


                                   EXHIBIT "D"
                               BUILDING STANDARDS
                                NOMOS CORPORATION


Standard leasehold improvements included in base rent:

1. Approximately ONE THOUSAND THREE HUNDRED SIXTY-FOUR (1,364) feet of interior
walls (steel stud and painted drywall).

2. Approximately ONE HUNDRED THIRTY-NINE (139) feet of demising walls (steel
stud and painted drywall).

3. CORRIDOR DOORS: TWO (2) 30/70 oak with key lock.

4. INTERIOR DOORS: THIRTY-NINE (39) 30/68 1-3/8" FHC prefinished oak tone doors
with standard latchset.

4a. Interior Doors: ONE (1) 4/68"

5. CEILINGS: Standard 2'x 4 suspended type TAFF approximately white fissured
design.

6. FLOORING: Standard carpeting including 4" rubber base.

7. WINDOW TREATMENT: All exterior windows are fitted with vertical blinds
(Standard building color).

8. HVAC: Heating, Ventilating, and Air Conditioning. A system will be provided
using standard design criteria for normal office conditions. Spot cooling for
equipment loads is not included. Thermostats will be located in a locked box in
a location to be determined to provide for optimum temperatures for all tenants.

9. ELECTRIC:

   -    Lighting: Provide one (1) 2' x 4' lay in fluorescent fixture (4 bulb
        cool/white) for every approximate one hundred (100) square feet.

   -    Outlets: Provide one (1) duplex wall outlet for every one hundred
        (100) square feet of leased space. -Standard circuiting installation.

10. BUILDING MAINTENANCE:


    -   Includes exterior of building and common areas only.

    -    Tenant assumes responsibility for complete maintenance and cleaning of
         lease space areas.



<PAGE>



                                   EXHIBIT "E"
                              RULES AND REGULATIONS


1.   DEFINITIONS: Wherever in these Rules and Regulations the word "Lessee" is
used, it shall be taken to apply to and include the Lessee and its agents
employees, invitees, licensees, subtenants and contractors, and is to be deemed
of such number and gender as the circumstances require. The word "Premises" is
to be taken to include the space covered by Lease. The word "Lessor" shall be
taken to include the employees and agents of Lessor.

2.   OBSTRUCTIONS: The streets, sidewalks,. entrances, halls, passages,
elevators, stairways and other common areas provided by Lessor shall not be
obstructed by Lessee, or used by it for any other purpose than for ingress and
egress.

3.   WASHROOMS: Toilet rooms, water-closets and other water apparatus shall not
be used for any purposes other than those for which they were constructed.

4.   ACCESS: Lessee agrees to permit Lessor access to the Premises at reasonable
times for performing environmental and janitorial services, and fire and safety
inspections.

5.   GENERAL PROHIBITIONS: In order to insure proper use and care of the
Premises Lessee shall not:

     (1)  Keep animals, fish or birds in the Premises.

     (2)  Use Premises as sleeping apartments.

     (3) Allow any sign, advertisement or notice to be fixed to the Building,
     inside or outside, without Lessor's consent.

     (4) Make improper noises or disturbances of any kind; sing, play or operate
     any musical instrument, radio or television to disturb other Lessees.

     (5) Mark or defile elevators, water-closets, toilet rooms, walls, window,
     doors or any other part of the Building.

     (6) Place anything on the outside of the Building, including roof setbacks,
     window ledges, and other projections; or drop anything from the windows,
     stairways or parapets; or place trash or other matter in the halls
     stairways or elevator of the Building.

     (7) Cover or obstruct any window, skylight, door or transom that admits
     light.

     (8) Fasten any particle, drill holes, drive nails or screws into the walls,
     floors, woodwork or partitions; nor shall the same be painted, papered or
     otherwise covered or in any way marked or broken without consent of Lessor.

     (9) Install or operate any machinery other than small office equipment
     without the consent of Lessor.

     (10) Interfere with the heating or cooling apparatus.


<PAGE>


     (11) Leave Premises without locking doors, stopping all off ice machines,
     and extinguishing all lights.

     (12) Install any shades, blinds, drapes or awnings without consent of
     Lessor.

     (13) Use any electric heating device without permission of Lessor.

     (14) Install intercoms, or any kind of wire in or on the Premises without
     Lessor's permission and direction.

     (15) Manufacture any commodity, or prepare or dispense any foods or
     beverages, tobacco, drugs, flowers, or other commodities or articles
     without the written consent of Lessor.

     (16) Secure duplicate keys for Building, Premises or toilets, except from
     Lessor.

     (17) Give employees or other persons permission to go upon the roof of the
     Building without the written consent of Lessor.

     (18) Place door mats in public corridors without consent of Lessor.

     (19) Install or use any electrical extension cords without Lessor's
     consent.

     (20) Fail to comply with load limitations for use of the elevators.

     (21) Shall not place any hazardous waste, material or substance in the
     sewage system or rubbish or otherwise improperly dispose of such.

     (22) Shall not place any infectious waste in the rubbish and shall not fail
     to segregate such waste in proper containers for separate disposal.

     (23) Fail to abide by parking restrictions and signs for parking vehicles
     in the parking lot.

6. BUILDING SECURITY: Lessee agrees to use the Building security system for
access to the Building after Normal Business Hours in accordance with Lessor's
instructions.

7. ELECTRICITY. Lessee shall pay for excessive use of electric current or
excessive electric current beyond the Building Services provided by the Lessor.


<PAGE>


                                    EXHIBIT F
                               BUILD OUT AGREEMENT
                 (NOMOS CORPORATION AND SPECTRA DEVELOPMENT CO.)


     8 extra 230 outlets @ $85                                 $680.00
     13 extra air outlets @ $105                             $1,365.00
     7 extra 220 outlets @ $85                                 $595.00
     Epoxy paint (2,137 sf @ $1.25)                          $2,671.00
     Extra Lights in Shop                                      $700.00
     Storage Area in Shop                                      $350.00
     40' of partition @ $53                                  $2,120.00
     Shower                                                  $5,210.00
     Kitchen                                                 $2,584.00
     Interior Glass                                          $8,280.00
     9' ceiling on 4th floor                                   $964.00
     Stair                                                   $6,100.00
     110 Duplexes (15 @ $3 2)                                  $480.00
     Quads (7 @ $64)                                           $448.00
     Ceiling Tile Extra                                      $1,653.75
     Warehouse panel                                         $1,900.00
     Total Improvements:                                    $36,100.75
     Less: Stair Allowance                                 ($2,150.00)
     Less: Shower/ Kitchen Cost Reduction                  ($l,300.00)
                                                           ----------

     Total                                                 $32,650.75


Tenant to provide bench and mirror.

A down payment of $10,000.00 will be due by August 12, 1994, the balance of
$22,650.75 to be financed.

The amount of $22,650.75 to be financed at nine percent for the term of twenty
four months payable in monthly 'installments of $1,034.81 to Spectra Development
Company due as additional rent until paid off.

Agreed to by:


---------------------------------------     ------------------------------------
         NOMOS Corporation                                Date


    /s/  Gary A. Sippel
---------------------------------------     ------------------------------------
Gary A. Sippel, Spectra Development Co.                   Date