<PAGE>

EXHIBIT 10.7

                              SUBLEASE AGREEMENT


     THIS SUBLEASE AGREEMENT (this "Sublease") is made and entered into between
RADIAN INTERNATIONAL LLC, a Delaware limited liability company ("Sublessor"),
and THE SMT CENTRE OF TEXAS INC., a Texas corporation ("Sublessee").

                              W I T N E S S E T H
                              - - - - - - - - - -

     WHEREAS, Sublessor currently leases from HB Austin Limited Partnership, a
Kansas limited partnership ("Prime Lessor"), certain real property (the
"Property") more particularly described as Lot 1, BRATTON-GRAND SUBDIVISION, a
subdivision in Travis County, Texas, according to the map or plot of record in
Volume 88, Pages 174-175, Plat Records of Travis County, Texas (locally known as
15508 Bratton Lane, Austin, Texas 78728), pursuant to that certain Lease between
Radian Corporation, a Texas corporation, as tenant, and Prime Lessor, as
landlord, dated June 3, 1991 (said Lease, as amended from time to time, is
referred to herein as the "Prime Lease"); and

     WHEREAS, the tenant's interest in the Prime Lease has been assigned by
Radian Corporation to Sublessor by Assignment of Lease dated as of January 1,
1996; and

     WHEREAS, the Property is improved with a building (the "Building") and
related site improvements, and Sublessor desires to lease to Sublessee 41,708.12
square feet of area within the Building (the "Premises"), as shown on the
floorplan of the Building attached hereto as Exhibit A and incorporated herein
                                             ---------
for all purposes, on the terms and conditions set forth below; and

     WHEREAS, this Sublease is being executed pursuant to section 4.1 of an
asset purchase agreement dated March 29, 1996 (the "Agreement") between, among
others, Sublessee, as purchaser, and Sublessor, Radian Corporation, and Radian
Systems Corporation, a Texas corporation, as sellers, pursuant to which
Sublessee has acquired the assets of said sellers' electronic assembly Business;

     NOW THEREFORE, for and in consideration of the premises and agreements set
forth below, Sublessor and Sublessee agree as follows:

                                   ARTICLE I
                                  PRIME LEASE

     1.01  Sublease Subject to Prime Lease.  This Sublease is subject and
           -------------------------------
subordinate to the Prime Lease, a copy of which is attached hereto as Exhibit B.
                                                                      ---------
Upon the termination of the Prime Lease, this Sublease shall terminate.
Capitalized terms used in this Sublease and not otherwise defined herein or in
the Agreement shall have the same meanings as set forth in the Prime Lease.

                                      -2-
<PAGE>

     1.02  Compliance with Prime Lease.  Except with respect to Sublessor's
           ---------------------------
obligations to pay to Prime Lessor the rent due thereunder, Sublessee hereby
covenants and agrees to comply with and perform all obligations of Sublessor to
Prime Lessor under the Prime Lease with respect to the Premises and Sublessee's
obligations under this Sublease, including, without limitation, all repair
obligations, all insurance obligations, and all indemnification obligations of
Sublessor thereunder. Sublessee agrees that whenever the consent of Prime Lessor
is required under the terms of the Prime Lease with respect to any action,
Sublessee shall obtain the consent of both Sublessor and Prime Lessor before
taking such action, and whenever the Prime Lease requires Sublessor to indemnify
Prime Lessor for any matter, to the extent the matter is applicable to the
Premises and Sublessee's obligations under this Sublease, Sublessee's activities
upon the Property or any obligations of Sublessee under this Sublease, Sublessee
shall indemnify both Prime Lessor and Sublessor with respect to such matter.
Sublessor agrees that except with respect to Section 6.01 below, where
Sublessor's consent is required under this Sublease, such consent will not be
unreasonably withheld. Sublessee agrees to deliver promptly to Sublessor copies
of any and all notices or other correspondence received by Sublessee from Prime
Lessor and further agrees, notwithstanding Section 9.04 of this Sublease to the
contrary, to so deliver same in the manner most appropriate to insure that
Sublessor will be able to respond to any of such notices or other correspondence
from the Prime Lessor within any time period set forth in the Prime Lease or
such notice.

                                  ARTICLE II
                              DEMISE OF PREMISES

     2.01  Demise of Premises.  Subject to and upon the terms and conditions set
           ------------------
forth herein and the provisions of the Agreement, Sublessor hereby subleases to
Sublessee, and Sublessee hereby subleases from Sublessor, for the Sublease Term
herein set forth, the Premises, including a license to Sublessee to use the
parking areas, driveways and sidewalks located upon the Property, and a license
to use those hallways, restrooms, conference rooms break rooms and loading docks
within the Building which are shown by cross-hatch on Exhibit A attached hereto
                                                      ---------
(collectively, the "Shared Areas"), in the same manner and to the same extent as
Sublessor uses such Shared Areas, but subject to such reasonable rules and
regulations regarding the Shared Areas as Sublessor may promulgate from time to
time, which rules and regulations do not restrict or interfere with Sublessee in
operating the Business in the same manner as Sublessor operated the Business
before Closing.

     2.02  Condition of the Premises.  Sublessee acknowledges and agrees that it
           -------------------------
has inspected the Premises and accepts same in their current condition.  "AS IS"
and "WITH ALL FAULTS". Sublessor has no obligation to construct any tenant
improvement in the Premises or make any repairs or modifications thereto. To the
extent Prime Lessor requires the removal of any improvements placed within the
Premises on behalf of Sublessee, Sublessee shall remove all such improvements at
Sublessee's sole expense and shall return the Premises to its condition prior to
the installation of such improvements, reasonable wear and tear excepted.
Sublessee may not

                                      -3-
<PAGE>

alter the Premises unless Sublessee first submits to Sublessor (and if required
under the Prime Lease, to Prime Lessor), plans and specifications for the
proposed alteration, and Sublessor (and Prime Lessor) approve such plans and
specifications.

     2.03  Disclaimer of Warranties.  EXCEPT AS EXPRESSLY STATED IN THE
           ------------------------
AGREEMENT, SUBLESSEE ACKNOWLEDGES THAT SUBLESSOR HAS NOT MADE AND WILL NOT MAKE
ANY WARRANTIES, EITHER EXPRESS OR IMPLIED, TO SUBLESSEE WITH RESPECT TO THE
QUALITY OF TENANT FINISH WITHIN THE PREMISES OR AS TO THE CONDITION OF THE
PREMISES, AND THAT SUBLESSOR EXPRESSLY DISCLAIMS ANY IMPLIED WARRANTY THAT THE
PREMISES ARE OR WILL BE SUITABLE FOR SUBLESSEE'S INTENDED PURPOSES. SUBLESSEE'S
OBLIGATION TO PAY RENTALS UNDER THIS SUBLEASE IS NOT DEPENDANT UPON THE
CONDITION OF THE PREMISES OR THE BUILDING (NOW OR IN THE FUTURE) OR THE
PERFORMANCE BY PRIME LESSOR OF ITS OBLIGATIONS UNDER THE PRIME LEASE OR BY
SUBLESSOR OF ANY OBLIGATIONS UNDER THIS SUBLEASE (OTHER THAN SUBLESSOR'S
OBLIGATION TO NOT DISTURB SUBLESSEE'S QUIET ENJOYMENT OF THE PREMISES) OR BY
PRIME LESSOR OF ITS DUTIES OR OBLIGATIONS UNDER THE PRIME LEASE, WHETHER EXPRESS
OR IMPLIED.

     2.04  Services.  Subject to the following limitations, Sublessor shall
           --------
furnish Sublessee while Sublessee is occupying the Premises and is not in
default (beyond any period permitted for cure) under this Sublease, facilities
to provide (i) water (hot and cold) at those points of supply provided for
general use of tenants in the Building and at existing locations within the
Premises; (ii) heated and refrigerated air conditioning in season; and at such
temperatures and in such amounts as are appropriate and commercially reasonable
in the conduct of the Business; (iii) janitorial service to the Premises as is
commercially reasonable on weekdays other than holidays recognized by Sublessor,
(iv) receptionist service as is commercially reasonable from 9:00 a.m. to 5:00
p.m. on weekdays other than holidays recognized by Sublessor, (v) de-ionized
water in such amounts and at such times as Sublessor and Sublessee may agree and
(vi) compressed air in such amounts and at such times as Sublessor and Sublessee
may agree. Also, Sublessor shall maintain the Shared Areas in reasonably good
order and condition; provided, however, that Sublessee shall reimburse Sublessor
for the cost of repairing any damage to such areas occasioned by Sublessee, or
its employees, agents or invitees, to the extent required under the Prime Lease.
Sublessee shall reimburse Sublessor for the cost of these services as more
particularly described below. Sublessor's failure to any extent to make
available, or any slowdown, stoppage or interruption of, the services set forth
in this Section 2.4 resulting from any cause (including, but not limited to,
Sublessor's compliance with (i) governmental or business guidelines now or
hereafter published or (ii) any requirements now or hereafter established by any
governmental agency, board or bureau with jurisdiction over the operation and
maintenance of the Building) shall not render Sublessor liable in any respect
for damages to person, property or business, nor be construed an eviction of
Sublessee or work an abatement of Rent, nor relieve Sublessee from fulfilling
any covenant or agreement hereof; however, Sublessor shall use reasonable
efforts to resume said services in a timely manner. Should any equipment or
machinery furnished by Sublessor break down or cease

                                      -4-
<PAGE>

to function properly, Sublessor shall use reasonable diligence to repair same
promptly, but Sublessee shall have no claim for abatement of Rent or damages on
account of an interruption in service occasioned thereby or resulting therefrom.
Notwithstanding the foregoing, if an interruption of a service which is
essential to Sublessee's use and occupancy of the Premises for the use permitted
herein occurs because of the negligence of Sublessor or its agents or employees,
and continues for a period of two (2) consecutive business days, the Rent
otherwise due hereunder will abate commencing the third consecutive day and
continuing until the first day upon which the essential service again is
provided.

                                  ARTICLE III
                    SUBLEASE TERM; SURRENDER OF POSSESSION

     3.01  Sublease Term.  The term of this Sublease ("Sublease Term") shall
           -------------
commence on April 1, 1996 (the "Commencement Date") and shall terminate on May
31, 2001, unless sooner terminated under the terms and provisions hereof.

     3.02  Surrender of the Premises.  At the termination of this Sublease, by
           -------------------------
lapse of time or otherwise, Sublessee shall deliver up the Premises to Sublessor
in as good condition as on the Commencement Date, expecting only ordinary wear
and tear and matters for which Sublessor is responsible thereunder.  Upon such
termination of this Sublease, Sublessor shall have the right to re-enter and
resume possession of the Premises.

     3.03  Holding Over.  If Sublessee holds over the Premises after expiration
           ------------
of this Sublease without prior written consent of Sublessor and Prime Lessor,
Sublessee shall be deemed to be occupying the Premises as a tenant at sufferance
at a daily rental equal to one thirtieth (1/30th) of two hundred percent (200%)
of the Rent (hereinafter defined), and otherwise subject to all the conditions,
provisions and obligations of this Sublease insofar as the same are applicable
to a tenancy at sufferance.  In addition, Sublessee shall indemnify and defend
Sublessor from all loss, cost, claims and damages (including consequential
damages) which Sublessor may suffer by reason of such holdover.  The inclusion
of this Section 3.03 shall not be deemed Sublessor's or Prime Lessor's consent
to any holding over.

                                  ARTICLE IV
                                     RENT

     4.01  Rent.  Sublessee, in consideration for the lease of the Premises,
           ----
agrees to pay Sublessor rental (the "Rent") in the amount of TWELVE AND NO/100
DOLLARS ($12.00) per square foot of the Premises per year.  The Rent shall be
paid in advance in equal monthly installments of Forty-one Thousand Seven
Hundred Eight and 12/100 Dollars ($41,708.12) each, as provided in Section 4.02.

     4.02  Payment of Rentals.  Sublessee shall pay to Sublessor, at Sublessor's
           ------------------
address set forth herein, the Rent without deduction or setoff (except as
provided in the Agreement), for each

                                      -5-
<PAGE>

month of the Sublease Term. One such monthly installment shall be payable by
Sublessee to Sublessor contemporaneously with the execution of this Sublease,
and a like monthly installment of Rent shall be due and payable without demand
beginning on the first day of the first full calendar month of the Sublease Term
and continuing thereafter on or before the first day of each succeeding calendar
month during the Sublease Term. If any installment of Rent, or any portion
thereof, is not received by the due date thereof, then (without in any way
implying Sublessor's consent to such late payment) Sublessee agrees to pay, in
addition to said installment of Rent, a late payment charge equal to the sum of
(a) one percent (1%) of the installment of Rent, or portion thereof, which is
overdue and (b) any sum which Sublessor may be required to pay to Prime Lessor
by reason of late payment under the Prime Lease, it being understood that said
late payment charge shall be for the purpose of reimbursing Sublessor for the
additional costs and expenses which Sublessor presently expects to incur in
connection with the handling and processing of late installment payments of the
Rent which become owing by Sublessee to Sublessor hereunder.

     4.03  Reimbursement for Services, Taxes and Insurance.  The Rent has been
           -----------------------------------------------
calculated based on the current cost to Sublessor of paying the expenses of the
Property and providing to the Premises the services described in Section 2.04
above. Sublessor and Sublessee intend that Sublessee shall (ans Sublessee
expressly agrees to) reimburse Sublessor (a) to the extent the cost of providing
to Sublessee the services described in Section 2.04 above exceeds the cost
previously incurred by Sublessor to provide such services to the Premises and
(b) to the extent Sublessee's share (determined by dividing the number of square
feet in the Premises by the number of square feet in the Building) of the taxes
and insurance payable by Sublessor with respect to the Property exceeds the cost
to Sublessor of the taxes and insurance for 1995. In that regard, Sublessor, at
Sublessor's expense, may install submeters to measure the amount of water,
wastewater, de-ionized water, compressed air and electricity utilized by
Sublessee within the Premises, and to measure the rated heat load of equipment
introduced by Sublessee into the Premises. Furthermore, Sublessor and Sublessee
shall agree upon the costs of all such services which shall be deemed incurred
by Sublessor for providing these services during the period when Sublessor
operated its business from the Premises. Where submeters are used, the excess
cost payable to Sublessee shall be calculated by multiplying the excess amount
by the rate(s) charged to Sublessor by the applicable service providers;
provided, however, that with respect to electricity, an additional cost shall be
charged to reflect the increase in the rated heat load because of the equipment
installed by Sublessee in the Premises, and at such time as Sublessor deems
appropriate, based upon the rated heat load generated by the equipment within
the Premises. Sublessor may require Sublessee to install, at Sublessee's
expense, additional air conditioning units with sufficient capacity to handle
the increased heat load. With respect to janitorial service, the cost payable by
Sublessee shall be determined based upon the janitorial service provider's bid.
Sublessor may estimate such excess cost and bill same to Sublessee on a monthly
basis, with a reconciliation at the end of each calendar year, or may bill
Sublessee for excess costs in arrears as incurred.

                                   ARTICLE V

                                      -6-
<PAGE>

                                QUIET ENJOYMENT

     5.01  Covenant of Quiet Enjoyment.  Provided Sublessee is not in default
           ---------------------------
under this Sublease (beyond any period permitted for Sublessee to cure same),
including without limitation, paying all Rent and other sums due hereunder.
Sublessee shall peaceably and quietly hold and enjoy the Premises against
Sublessor, for the Sublease Term herein described subject to the provisions and
conditions of this Sublease and of the Prime Lease, and subject to the Rights of
any party with an interest in the Premises superior to that of Sublessor (such
as Prime Lessor and any lender with a lien against the Building).  Sublessor's
covenant of quiet enjoyment shall include the obligation to perform all
obligations of the tenant under the Prime Lease to the extent Sublessee is not
required to perform such obligations under the terms of this Sublease.

     5.02  Limitation.  Subject to the provision of the Agreement, it is
           ----------
understood and agreed that the provisions of Section 5.01 and any and all other
covenants of Sublessor contained int his Sublease shall be binding upon
Sublessor and its successors only with respect to breaches occurring during its
and their respective ownership of the Sublessor's interest hereunder.  This
Sublease is subject to and subordinate to all matters of public record in Travis
County, Texas.

     5.03  Use.  Sublessee shall use the Premises only for electronic assembly
           ---
operations and related activities and for no other purposes without Sublessor's
consent.  Sublessee shall not permit any sound, light, odor or other matter to
escape or emanate from the Premises other than in the commercially reasonable
conduct of the Business without Sublessor's prior written consent.

                                  ARTICLE VI
                           ASSIGNMENT AND SUBLETTING

     6.01  Restriction.  Sublessee shall not, without the prior written consent
           -----------
of Sublessor and Prime Lessor, which may be withheld by either in their sole
discretion, assign, transfer, mortgage, pledge, hypothecate or encumber this
Sublease or any interest herein or sublet the Premises or any part thereof, or
permit the use of the Premises by any party other than Sublessee.  Any such
consent by Sublessor to any such assignment or subletting shall not release
Sublessee from any of Sublessee's obligations hereunder or be deemed to be a
consent to any subsequent assignment, subletting, occupation or use by another
person.

                                  ARTICLE VII
                        INDEMNIFICATION AND EXCULPATION

     7.01  Sublessee's Indemnity.  Sublessee shall indemnify and hold harmless
           ---------------------
Sublessor and Sublessor's agents, employees, shareholders, officers and
directors from and against all costs, expenses (including reasonable attorney's
fees and costs), fines, suite, claims, demands, liabilities and actions
resulting from any breach, violation or nonperformance by Sublessee and
Sublessee's employees, agents, contractors, licensees and invitees, of any
covenant or condition hereof or of the Prime Lease or from the use or occupancy
of the Premises or the Shared Areas by Sublessee or Sublessee's employees,
agents, contractors, licensees and invitees or from any act, omission or

                                      -7-
<PAGE>

neglect of Sublessee, Sublessee's agents, servants, employees, customers or
invitees or from any other cause whatsoever (other than Sublessor's negligence).

     7.02  Sublessor's Indemnity.  Sublessor shall indemnify and hold harmless
           ---------------------
Sublessee and Sublessee's agents, employees, shareholders, officers and
directors from and against all costs, expenses (including reasonable attorney's
fees and costs), fines, suites, claims, demands, liabilities and actions
resulting from any breach, violation or nonperformance by Sublessor and
Sublessor's employees, agents, contractors, licensees and invitees, of any
covenant or condition hereof or of the Prime Lease or from any act, omission or
neglect of Sublessor, Sublessor's agents, servants, employees customers or
invitees.  In no event shall Sublessee or Sublessee's agent, servants,
employees, customers or invitees be considered customers or invitees of
Sublessor for purposes of this Section 7.02.

     7.03  Waiver of Subrogation.  Each party hereto waives any cause of action
           ---------------------
it might have against the other party on account of any loss or damage that is
insured against under any insurance policy (to the extent that such loss or
damage is recoverable under such insurance policy) that covers the Building, the
Premises, Sublessor's or Sublessee's fixtures, personal property, leasehold
improvements or business and which names Sublessor or Sublessee, as the case may
be, as a party insured. Notwithstanding the foregoing, the releases in the
preceding sentence shall be applicable and in force and effect only so long as
and to the extent that such release does not invalidate any policy or policies
of insurance now or hereafter maintained by the other party hereto. Each party
hereto agrees that it will request its insurance carrier to endorse all
applicable policies waiving the carrier's rights of recovery under subrogation
or otherwise against the other party.

     7.04  Exculpation.  Sublessor shall not be liable to Sublessee or
           -----------
Sublessee's employees, agents, contractors, licenses or invitees for any injury
to person or damage to property from any cause whatsoever, excepting only the
negligence or willful misconduct of Sublessor or duly authorized employees and
agents of Sublessor.

                                 ARTICLE VIII
                             DEFAULTS AND REMEDIES

     8.01  Default by Sublessee; Remedies by Sublessor.  The provisions of the
           -------------------------------------------
Prime Lease with respect to the tenant's default and the landlord's remedies are
incorporated into this Section by this reference. In case of any breach of this
Sublease by Sublessee, Sublessor shall notify Sublessee of the breach if, and to
the extent, Prime Lessor must notify Sublessor of a breach under the Prime
Lease, and Sublessee shall have any rights to cure which inure to Sublessor
under the Prime Lease. Sublessee shall be personally liable to Sublessor for all
damage incurred or suffered by Sublessor by reason of such breach, and in
addition to all other rights of Sublessor available at law or equity, Sublessor
shall have all rights held by Prime Lessor under the Prime Lease as if such
breach by Sublessee was a breach by the tenant thereunder. Notwithstanding the
foregoing, Sublessor's right to recover consequential damages from Sublessee
shall be limited to

                                      -8-
<PAGE>

the right to recover damages suffered by Sublessor because of a breach by
Sublessee of the Prime Lease, Sublessee expressly agreeing that any such damages
are foreseeable. If Sublessee defaults in the performance of any of the terms
and provisions hereof and Sublessor places the enforcement of this Sublease in
the hand of an attorney, Sublessee agrees to reimburse Sublessor for all
reasonable expenses incurred by Sublessor as a result thereof including, but not
limited to, reasonable attorney's fees.

                                  ARTICLE IX
                                 MISCELLANEOUS

     9.01  Amendment.  No amendment, modification or alteration of the terms
           ---------
hereof shall be binding unless the same shall be in writing, dated subsequent to
the date hereof and duly executed by the parties hereto.

     9.02  Headings; Interpretation.  Descriptive headings are for convenience
           ------------------------
only and shall not control or affect the meaning or construction of any
provision of this Sublease. Whenever the context of this Sublease requires,
words used in the singular shall be construed to include the plural and vice
versa and pronouns of whatsoever gender shall be deemed to include and designate
the masculine, feminine or neuter gender.

     9.03  Counterparts.  For the convenience of the parties, any number of
           ------------
counterparts of this Sublease may be executed by one or more parties hereto and
each such executed counterpart shall be, and shall be deemed to be, an original
instrument.

     9.04  Notices. Subject to Article 1.03 hereof, notices, consents, requests,
           -------
instructions, approvals and other communications provided for herein and all
legal process in regard hereto shall be validly given, made or served, if in
writing and delivered personally or sent by United States certified or
registered mail, postage prepaid, return receipt requested, if to:

     Sublessor:

     Radian International LLC
     P.O. Box 201088
     Austin, Texas 78720-1088
     Attn: Facilities Manager

     Sublessee:

     The SMT Centre of Texas Inc.
     15508 Bratton Lane, Suite ___
     Austin, Texas 78728

     with a copy to:

                                      -9-
<PAGE>

     The SMT Centre of Texas Inc.
     635 Hood Road
     Markham, Ontario, Canada
     L3R 4N6

     and to:

     Gordon H. Hall
     Hall McNeely
     11 Allstate Parkway, Suite 550
     Markham, Ontario L32 978

     Prime Lessor:

     HB Austin Limited Partnership
     1102 Grand Avenue, Suite 300
     Kansas City, Missouri 64106
     Attn: John DeHardt

     or to such other address as any party hereto may, from time to time,
     designate in writing delivered in a like manner.

     9.05  Successors and Assigns. This Sublease shall be binding upon and inure
           ----------------------
to the benefit of the parties hereto and their respective permitted successors
and assigns in accordance with the terms of this Sublease.

     9.06  Time of the Essence.  Time is of the essence in the performance by
           -------------------
Sublessee of its obligations hereunder.

     9.07  Remedies Cumulative Applicable Law.  All rights and remedies of the
           ----------------------------------
parties hereunder shall be cumulative and none shall exclude any other rights or
remedies allowed by law.  This Sublease is declared to be a Texas contract, and
all of the terms hereof shall be construed according to the laws of the State of
Texas.

     9.08  Entire Agreement.  This Sublease and the Agreement constitute the
           ----------------
entire agreement of the parties with respect to the subject matter hereof, and
all prior correspondence, memoranda, agreements or understandings (written or
oral) with respect hereto are merged into and superseded by this Sublease.

     9.09  Severability.  If any term or provision of this Sublease, or the
           ------------
application thereof to any person or circumstance, shall to any extent be
invalid or unenforceable, the remainder of this Sublease, or the application of
such provision to persons or circumstances other than those as to

                                      -10-
<PAGE>

which it is invalid or unenforceable, shall not be affected thereby, and each
provision of this Sublease shall be valid and shall be enforceable to the extent
permitted by law.

     9.10  No Recording. This Sublease (including any exhibits hereto) shall not
           ------------
be recorded without the prior written consent of Sublessor.

     9.11  Entry on Premises.  Sublessor and Prime Lessor shall have access to
           -----------------
the Premises at all reasonable times for reasonable business purposes.

     9.12  Subordination.  This Sublease shall automatically be subordinate and
           -------------
inferior to, and Sublessee shall sign any document requested by Sublessor or
Prime Lessor to cause this Sublease to be subordinate and inferior to, any
mortgage, condominium declaration, condominium regime, encumbrance, instrument
of security, ground lease, master lease, or primary lease (collectively
"Encumbrance/Lease") now or hereafter placed on the Premises and/or the
Building. Subleases shall sign such other documents with respect to such
Encumbrances/Leases as Sublessor or Prime Lessor shall request.

     9.13  Signs.  Sublessee shall have the right, at Sublessee's expense, but
           -----
subject to Prime Lessor's and Sublessor's approval as to appearance, location
and method of attachment to install a sign on the Building.  Sublessee shall
comply with all ordinances, rules and regulations of the City of Austin in
connection with such sign, and shall be responsible, at Sublessee's expense, for
removing the sign, and repairing the Building surface, upon termination of this
Sublease.

     9.14  Sublessor's Termination Right.  Sublessor has the right to terminate
           -----------------------------
the Prime Lease under certain conditions.  Sublessor agrees that before
exercising such termination right, Sublessor shall notify Sublessee of
Sublessor's decision, and shall give Sublessee fifteen (15) days to determine
whether Sublessee wishes to assume Sublessor's position under the Prime Lease.
If Sublessee notifies Sublessor within said fifteen day period that Sublessee
wishes to assume the Prime Lease, Sublessor shall not terminate the Prime Lease
without requesting Prime Lessor's consent to such an assignment. If Prime Lessor
consents to the assignment of the Prime Lease, Sublessor shall assign the Prime
Lease to Sublessee, Sublessee shall terminate effective upon the date of the
assignment. If Sublessee does not notify Sublessor within said fifteen-day
period that Sublessee requests an assignment, or if Prime Lessor does not
consent to the assignment, Sublessor may exercise its termination right without
any further obligation to Sublessee hereunder, however, Sublessor shall notify
Sublessee of such exercise concurrently with the notice to Prime Lessor.

     9.15  Commissions.  Each party warrants to the other that it had no dealing
           -----------
with any broker or agent in connection with the negotiation or execution of this
Sublease.  If any agent or broker shall make a claim for a commission or fee,
the party through whom the agent or broker claims shall be responsible for
payment thereof and hereby indemnifies and holds the other party harmless from
such claim for commission or fees.

                                      -11-
<PAGE>

     9.16  Option to Terminate.  Notwithstanding any provision contained in this
           -------------------
Sublease to the contrary, if Sublessor sells its electronic panel services
division to a party unrelated to Sublessor (a "Third Party Sale"), Sublessor
shall notify Sublessee (the "Notice") of the contemplated Third Party Sale at
least sixty (60) days before the closing of the Third Party Sale.  Sublessee
shall have the right, to be exercised within fifteen (15) days after delivery to
Sublessee of the Notice, to terminate this Sublease.  Exercise of such right of
termination shall be effected only by notice delivered to Sublessor within said
fifteen-day period.

     9.17  Parking.  Sublessee and its agents, employees and invitees shall park
           -------
only in those areas designated by Sublessor for parking and shall not park on
any public or private streets contiguous to, surrounding or in the vicinity of
the Property. Sublessor reserves the option to designate portions of the parking
areas upon the Property for parking for visitors and customers of Sublessor and
other tenants of the Building. Sublessee agrees that Sublessee and Sublessee's
agents and employees shall not park within any visitor parking area so
designated by Sublessor. Sublessor shall not be liable or responsible for any
loss of or to any car or vehicle or equipment or other property therein or
damage to property or injuries (fatal or nonfatal) from any cause whatsoever
while such car or vehicle is on the Property or parked within said parking
areas. Sublessor may make, modify, and enforce rules and regulations relating to
the parking of automobiles and Sublessee will abide by such rules and
regulations. If the availability of spaces within the Property becomes a
problem, Sublessor may adopt a parking rule limiting each tenant of the Building
to a pro rata share of the parking on the Property.

     9.18  Attorney's Fees.  If any action or proceeding is brought to enforce
           ---------------
any term, covenant or condition of this Sublease on the part of Sublessor or
Sublessee, the prevailing party in such action or proceeding shall be entitled
to reasonable attorneys' fees to be fixed by the court therein.

     9.19  Security.  Sublessor shall be in no way responsible to Sublessee, its
           --------
agents, employees or invitees for any loss of property from the Premises or
Shared Areas or for any damages to any property thereon from any cause
whatsoever regardless of whether such loss occurs when the area is locked
against entry or not. Sublessee understands and agrees that all persons entering
or leaving the Premises must comply with Sublessor's security procedures,
including wearing identification badges, being accompanied by Sublessor's
personnel, card access controls and such other methods as Sublessor may elect to
use from time to time. Sublessee further understands that Sublessee's agents,
employees, contractors, invitees and visitors shall not be permitted in the
Building other than when they are going to or from the Premises, or using the
Shared Areas. Sublessee agrees to conform to all rules and regulations which
Sublessor may establish in order to maintain the security necessary for
Sublessor's operations within the Building.

     9.20  Environmental Matters. Sublessor has advised Sublessee, and Sublessee
           ---------------------
understands, that in no event may Sublessee discharge into the Building's
wastewater or storm drainage system more metals or other materials which is
permitted from time to time by the utility providing wastewater service to the
Building (and Sublessee shall be solely responsible for

                                      -12-
<PAGE>

ensuring that no such discharge occurs). Sublessor reserves the right to monitor
discharge at both the point where the discharge leaves the Premises and at the
point where the combined discharge generated by Sublessor and Sublessee leaves
the Building. If any materials exceeding utility limits in fact are discharged
from the Premises, Sublessor, at Sublessee's expense, will construct such
filtering or other systems as may be required in order to eliminate such excess
discharge of materials. Sublessee further agrees that Sublessee shall not change
the Business in a manner that results in the discharge or any materials in
addition to the materials currently being discharged without Sublessor's prior
written consent. In this penalties, liabilities, and costs (including reasonable
attorneys' fees and court costs) caused by or arising out of (i) a violation of
the foregoing prohibition or (ii) the presence or any release of any Hazardous
Materials on, under, or about the Premises during Sublessee's occupancy or
control of the Premises. Sublessee shall clean up, remove, remediate and repair
any soil or ground water contamination and damage caused by the presence or
release of any Hazardous Materials in, on, under, or about the Premises during
Sublessee's occupancy of the Premises in conformance with the requirements of
applicable law. Sublessee shall immediately give Sublessor written notice of any
suspected breach of this Paragraph, upon learning of the presence of any release
of any Hazardous Materials, and upon receiving any notice from governmental
agencies pertaining to Hazardous Materials which may affect the Premises. The
obligations of Sublessee hereunder shall survive the expiration or earlier
termination, for any reason, of this Lease.

                                      -13-
<PAGE>

     IN WITNESS WHEREOF, the undersigned Sublessor and Sublessee have executed
this Sublease on the dates set forth hereinbelow.

SUBLESSOR:                               RADIAN INTERNATIONAL, LLC, a Delaware
---------
                                         limited liability company


                                         By /s/ Donald M. Carlton
                                            ------------------------------------
                                            President


                                            Date: March 29, 1996
                                                  ------------------------------

SUBLESSEE:                               THE SMT CENTRE OF TEXAS INC., a Texas
---------
                                         corporation


                                         By /s/ Paul Walker
                                            ------------------------------------
                                            President


                                            Date: March 29, 1996
                                                  ------------------------------

                                      -14-
<PAGE>

                                  EXHIBIT "B"

                            BASIC LEASE INFORMATION


Lease Date:                        June 3, 1991

Tenant:                            Radian Corporation, a Texas corporation

Address of Tenant:                 Post Office Box 201088
                                   Austin, Texas 78720-1088

Contact:                           Erwin Kouba   Telephone: (512) 454-4797

Landlord:                          HB Austin Limited Partnership, a Kansas
                                   limited partnership

Address of Landlord:               1102 Grand Avenue, Suite 300
                                   Kansas City, Missouri 64106

Contact:                           John DeHardt  Telephone: (816) 842-2690

Premises:                          Lot 1, BRATTON-GRAND SUBDIVISION, a
                                   subdivision in Travis County, Texas,
                                   according to the map or plat of record in
                                   Volume 58, Pages 174-175, of the Plat Records
                                   of Travis County, Texas, together with all
                                   improvements located thereon, including a
                                   building (the "Building"), locally known as
                                   15508 Bratton Lane, Austin, Texas.

Lease Term:                        The period commencing on the Commencement
                                   Date and, subject to and upon the terms and
                                   conditions set forth herein, and in any
                                   exhibit or addendum hereto, continuing until
                                   July 31, 2001.

Commencement Date:                 June 15, 1991

Rental:                            $33,813.00 per month. The Rental shall
                                   increase in accordance with the provisions of
                                   Exhibit C attached hereto.
                                   ---------

Rental Commencement
  Date:                            August 1, 1991

                                      -15-
<PAGE>

Permitted Use:                     Tenant shall use and occupy the premises for
                                   manufacturing and laboratory purposes and for
                                   purposes incidental thereto.

The foregoing Basic Lease Information is hereby incorporated into and made a
part of the lease attached hereto.

Each reference in the lease to the information or definitions set forth in the
Basic Lease Information shall mean and refer to the information and definitions
hereinabove set forth and shall be used in conjunction with and limited by all
references thereto in the provisions of the lease.  In the event of any conflict
between the Basic Lease Information and the lease, the lease shall control.

                         LANDLORD:

                         HB AUSTIN LIMITED PARTNERSHIP, a
                         Kansas limited partnership


                         By: /s/ John Dehardt
                             ----------------------------------

                             Name: John Dehardt
                                   ----------------------------

                             Title: General Partner
                                    ---------------------------

                         TENANT:

                         RADIAN CORPORATION, a Texas
                         corporation


                         By: /s/ [signature appears here]
                             ----------------------------------

                             Name: ____________________________

                             Title: Vice President
                                    ---------------------------

                                      -16-