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                                                                   EXHIBIT 10.20


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                               ONE FINANCIAL PLAZA

                              STANDARD OFFICE LEASE

                                       FOR

                         JACOBS ENGINEERING GROUP, INC.

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                               ONE FINANCIAL PLAZA
                              STANDARD OFFICE LEASE

                                TABLE OF CONTENTS

ARTICLE    INDEX                                                         PAGE
-------    -----                                                         ----

ARTICLE 1. PARTIES AND REFERENCE DATA .................................    1

ARTICLE 2. DEMISING CLAUSE ............................................    5

ARTICLE 3. TERM AND POSSESSION ........................................    5

ARTICLE 4. RENT .......................................................    7

ARTICLE 5. INTENTIONALLY OMITTED ......................................    9

ARTICLE 6. PERMITTED USE ..............................................    9

ARTICLE 7. SERVICES ...................................................   10

ARTICLE 8. SUBLETTING AND ASSIGNMENT ..................................   12

ARTICLE 9. QUIET POSSESSION AND SUBORDINATION .........................   13

ARTICLE 10. LANDLORD'S RESERVED RIGHTS ................................   13

ARTICLE 11. ALTERATIONS AND IMPROVEMENTS ..............................   14

ARTICLE 12. REPAIRS AND REPLACEMENTS ..................................   15

ARTICLE 13. DESTRUCTION OR DAMAGE .....................................   16

ARTICLE 14. EMINENT DOMAIN ............................................   16

ARTICLE 15. HOLDING OVER ..............................................   17

ARTICLE 16. SURRENDER OF POSSESSION ...................................   17

ARTICLE 17. DEFAULT AND REMEDIES ......................................   18

ARTICLE 18. BANKRUPTCY ................................................   20

ARTICLE 19. INSURANCE AND WAIVER OF RECOVERY ..........................   21

ARTICLE 20. TAXES ON TENANT'S PROPERTY ................................   22

ARTICLE 21. AMERICANS WITH DISABILITIES ACT ...........................   23

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ARTICLE 22. HAZARDOUS MATERIALS .......................................   23

ARTICLE 23. GENERAL PROVISIONS ........................................   24


Exhibit A             Floor Plan

Exhibit A-1           Signage Location Plan

Exhibit B             Intentionally Omitted

Exhibit C             Work to be Performed on the Premises
                      Schedule 1 - Landlord's "White-Box" Work

Exhibit D             Building Rules

Exhibit E             Lease Commencement Agreement

Exhibit F             Lien Waivers

Exhibit G             Lease Estoppel Certificate

Exhibit H             One Financial Plaza Meeting Rooms Rules and Regulations

Exhibit I             Subordination, Attornment and Non-Disturbance Agreement

Exhibit J             Reserved Parking

Addendum No. 1

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                               ONE FINANCIAL PLAZA
                              STANDARD OFFICE LEASE

                                   ARTICLE 1.
                           PARTIES AND REFERENCE DATA

                  As used in this Lease the following terms shall have the
following meanings:

                  1.1. LANDLORD: EBS Building, L.L.C., a Delaware limited
liability company, having as its address for notice purposes c/o
PricewaterhouseCoopers LLP, 800 Market Street, Suite 1800, St. Louis, Missouri
63101, Attn: Mr. Keith F. Cooper, Partner.

                  1.2. TENANT: Jacobs Engineering Group, Inc. having as its
address for notice purposes 1111 South Arroyo Parkway, Pasadena, California
91105, Attn: John W. Prosser, Jr., with courtesy copy to Richard E. Feldman,
Esq., Blackwell, Sanders, Peper, Martin, 720 Olive Street, Suite 2400, St.
Louis, Missouri 63101.

<TABLE>
<S>                        <C>                                <C>
                  1.3.     DATE OF THIS LEASE:                February 22, 2001

                  1.4.     TENANT'S CD SUBMITTAL DATE:        June 4, 2001
                           LANDLORD'S CD APPROVAL DATE:       June 11, 2001
                           TENANT'S SUBSEQUENT CD
                             SUBMITTAL DATE:                  June 18, 2001
                           FINAL DATE FOR APPROVED
                             CONSTRUCTION DOCUMENTS:          June 22, 2001

                  1.5.     LEASE COMMENCEMENT DATE:           October 1, 2001, subject to adjustment
                                                              in accordance with the provisions of
                                                              this Lease

                           RENT COMMENCEMENT DATE:            September 1, 2002, subject to
                                                              adjustment in accordance with the
                                                              provisions of this Lease

                           LEASE EXPIRATION DATE:             August 31, 2012, subject to adjustment
                                                              in accordance with the provisions of
                                                              this Lease

                  1.6.     TERM:                              The period commencing on the Lease
                                                              Commencement Date and ending on the
                                                              August 31, 2012, subject to adjustment
                                                              in accordance with the provisions of
                                                              this Lease.
</TABLE>


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                  1.7.     BUILDING: the office building in the City of St.
Louis, State of Missouri, known and numbered as 501 North Broadway, St. Louis,
Missouri 63102, together with the legally subdivided lot upon which it is
situated (the "Real Estate"), including all facilities and improvements thereon
and consisting of approximately 434,136 rentable square feet.

                  1.8.     PREMISES: Landlord and Tenant hereby stipulate that
the Premises consists of 161,892 rentable square feet, located on the Second,
Third, Fourth and Eleventh Floors and a portion of the First Floor in the
Building as depicted in Exhibits A and B of this Lease and as improved in
accordance with the provisions of Exhibit C of this Lease. Landlord and Tenant
hereby further stipulate and agree that the portion of the Premises located on
the First Floor contains 9,999 rentable square feet, the Second Floor contains
27,877 rentable square feet, the Third Floor contains 46,008 rentable square
feet, the Fourth Floor contains 46,008 rentable square feet and the Eleventh
Floor contains 32,000 rentable square feet.

                  1.9. SUITE NUMBERS: 200, 300, 400, 1100 and 175, FLOOR
NUMBERS: Floors Two, Three, Four and Eleven and a portion of Floor One.

                  1.10. PERMITTED USE: Professional engineering and general
office purposes only and for no other purpose without the prior written consent
of Landlord.

                  1.11. ANNUAL BASE RENT AND MONTHLY BASE RENT INSTALLMENT
(based upon the Premises containing 161,892 rentable square feet):

                        a.    Second, Third, Fourth and Eleventh Floors
                        (comprised of 151,893 rentable square feet, as
                        stipulated in Section 1.8 above)

                              From 10/01/2001 - 08/31/2002; Annually None.
                              From 09/01/2002 - 08/31/2004; Annually
                              $2,582,181.00;
                                   Monthly $215,181.75, based upon a
                              base rental rate of $17.00 per rentable
                              square foot. From 09/01/2004 - 08/31/2006;
                              Annually $2,658,127.50;
                                   Monthly $221,510.62, based upon a
                              base rental rate of $17.50 per rentable
                              square foot. From 09/01/2006 - 08/31/2008;
                              Annually $2,734,074.00;
                                   Monthly $227,839.50, based upon a
                              base rental rate of $18.00 per rentable
                              square foot. From 09/01/2008 - 08/31/2010;
                              Annually $2,810,020.50;
                                   Monthly $234,168.37, based upon a
                              base rental rate of $18.50 per rentable
                              square foot. From 09/01/2010 - 08/31/2012;
                              Annually $2,885,967.00;
                                   Monthly $240,497.25, based upon a
                              base rental rate of $19.00 per rentable
                              square foot.


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                        b.    First Floor   (comprised of 9,999 rentable square
                        feet as stipulated in Section 1.8 above)

                                    From 10/01/2001 - 08/31/2002; Annually None.
                                    From 09/01/2002 - 08/31/2004; Annually
                                    $129,987.00;
                                            Monthly $10,832.25, based upon a
                                    base rental rate of $13.00 per rentable
                                    square foot. From 09/01/2004 - 08/31/2006;
                                    Annually $137,486.25;
                                            Monthly $11,457.19, based upon a
                                    base rental rate of $13.75 per rentable
                                    square foot. From 09/01/2006 - 08/31/2010;
                                    Annually $144,985.50;
                                            Monthly $12,082.13, based upon a
                                    base rental rate of $14.50 per rentable
                                    square foot. From 09/01/2010 - 08/31/2012;
                                    Annually $157,484.25;
                                            Monthly $13,123.69, based upon a
                                    base rental rate of $15.75 per rentable
                                    square foot.

The foregoing dates are subject to adjustment in accordance with the provisions
of this Lease.

                  1.12. COMMERCIAL OR COMPREHENSIVE GENERAL LIABILITY INSURANCE
REQUIRED: $1,000,000.00, annual aggregate.

                  1.13. SECURITY DEPOSIT: Waived.

                  1.14. TENANT'S PROPORTIONATE SHARE: 37.29% (the percentage
determined by dividing 161,892, the number of rentable square feet constituting
the Premises, stipulated and agreed upon by Landlord and Tenant, by 434,136, the
number of rentable square feet within the Building stipulated and agreed upon by
Landlord and Tenant).

                  1.15. EXPENSE STOP AMOUNT: The Expense Stop Amount shall be
based upon the Expenses, as defined in Section 4.3 of the Lease, of the Building
for the 2002 (01/01/02-12/31/02) calendar year.

                  1.16. TAX EXPENSE STOP AMOUNT: The Tax Expense Stop Amount
shall be based upon Taxes as defined in Section 4.4 of the Lease, of the
Building for the 2002 (01/01/02-12/31/02) calendar year; provided, however, that
in the event the Building is then taxed at one hundred percent (100%) of its
value, effective January 1, 2009 (and during the remainder of the Term hereof)
the Tax Expense Stop Amount shall be increased to the sum of (x) two (2) times
the Taxes on the Building for the 2002 calendar year (exclusive of any Taxes due
solely on the assessed value of the Real Estate without regard to any
improvements thereon), plus (y) the Taxes due solely on the assessed value of
the Real Estate (without regard to any improvements thereon) for the 2002
calendar year.

                  1.17. NUMBER OF PARKING SPACES: Tenant shall have the
exclusive use of level B2 of the parking garage in the Building (the "Building
Garage"), consisting of 95 parking spaces, at current market rates. Tenant shall
also have the use of 105 parking spaces located in


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the garage owned and operated by the Land Clearance for Redevelopment Authority
of the City of St. Louis and located on City Block 118 in the City of St. Louis
(the "St. Louis Centre Garage"), at current market rates. If Landlord provides
visitor parking in the Building Garage, Tenant shall be entitled to utilize
Tenant's Proportionate Share of such visitor parking; provided said visitor
parking shall (i) be used only by Tenant's visitors and not by any employees of
Tenant, (ii) be charged at current hourly market rates and (iii) not be
monitored by Landlord and Landlord shall have no obligation to Tenant in the
event visitor parking is not available. Tenant may, at Tenant's sole cost and
expenses, subject to such reasonable regulations as Landlord shall impose,
provide valet parking on level B2 of the Building Garage and double park said
vehicles; provided such valet parking and double parking does not interfere with
or hinder the use of the Building Garage by Landlord, its invitees and the other
tenants of the Building; and further provided said double parking does not, in
Landlord's reasonable judgment, adversely affect the structural integrity of the
Building or disrupt traffic flow to other levels in the Building Garage. Tenant
may not restripe level B2 of the Building Garage without Landlord's consent,
which consent shall not be unreasonably withheld. Tenant's payment to Landlord
for parking on level B2 of the Building Garage shall be based upon 95 parking
spaces, without regard to the actual number of cars parked on such level. All
parking spaces in the Building Garage shall be accessible 24 hours per day,
seven (7) days per week (subject to interruptions for maintenance and the like)
at no additional charge. From and after the Lease Commencement Date, Landlord
covenants to perform those obligations of the tenant under the lease for the St.
Louis Centre Garage which, if not performed, would give the landlord thereunder
the right to terminate such lease. Parking spaces in the St. Louis Centre Garage
shall be available from 7:00 a.m. until 6:00 p.m., Monday through Friday, as
referenced in the lease for the St. Louis Centre Garage.

                  At any time after the second lease year, Tenant shall have an
on-going right to surrender, from time to time, all or any portion of the 105
parking spaces located in the St. Louis Centre Garage to Landlord; provided,
that Tenant shall provide Landlord with at least six (6) months prior written
notice of the number of spaces to be surrendered and Tenant's desired date of
surrender of said parking spaces (each such date, a "Surrender Date"), which
date shall be no earlier than six (6) months after the date of said notice. In
the event Tenant exercises the surrender right provided in this Section 1.17,
such surrender shall not become effective until Landlord and Tenant enter into
an amendment to this Lease, which amendment shall stipulate the number and, if
applicable, the location, of parking spaces that Tenant shall utilize in the St.
Louis Centre Garage as of the applicable Surrender Date. Tenant shall have no
right to utilize the surrendered spaces after the applicable Surrender Date and
no further obligation to pay Landlord monthly rental for the surrendered spaces
after the applicable Surrender Date.

                  1.18. INITIAL MONTHLY RENT PER PARKING SPACE: As of the date
hereof, Building Garage: $100.00 per parking space (which rate shall not
increase during the first lease year), St. Louis Centre Garage: $85.00 per
parking space. After the first lease year, the monthly rate per parking space in
the Building Garage shall not be in excess of the monthly rate per parking space
charged generally by Landlord to other tenants in the Building.

                  1.19. ADDENDUM: 6 pages.


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                  1.20. BROKERS: Name(s) of broker(s): Colliers Turley Martin
Tucker represents Landlord and Tenant; Party responsible for payment: Landlord.

                  1.21. EXHIBITS: The following Exhibits attached to this Lease
are incorporated herein by this reference.

                  Exhibit A. Floor Plan
                  Exhibit A-1. Signage Plan
                  Exhibit B. Intentionally Omitted
                  Exhibit C. Work to be Performed on the Premises
                             Schedule 1.  Landlord's "White-Box" Work
                  Exhibit D. Building Rules
                  Exhibit E. Lease Commencement Agreement
                  Exhibit F. Lien Waivers
                  Exhibit G. Lease Estoppel Certificate
                  Exhibit H. One Financial Plaza Meeting Room Rules and
                             Regulations
                  Exhibit I. Subordination, Attornment and  Non-Disturbance
                             Agreement
                  Exhibit J. Reserved Parking

                  1.22. STORAGE AREA: Approximately 3,587 rentable square feet
of storage space located on the Second Floor of the Building (Mezzanine Area),
as depicted in Exhibit A of this Lease. Tenant shall have a right of first
refusal to lease approximately 2,000 rentable square feet of storage space
located on the mezzanine level of the First Floor of the Building. See Section
23.33 of the Lease.

                                   ARTICLE 2.
                                 DEMISING CLAUSE

                  Landlord, for and in consideration of the rents, covenants and
agreements hereinafter mentioned and hereby agreed to be paid, kept and
performed by Tenant, does hereby lease to Tenant, and Tenant does hereby lease
from Landlord, the Premises on the terms and conditions contained herein.

                                   ARTICLE 3.
                               TERM AND POSSESSION

                  3.1. TERM. The Term shall commence on the Lease Commencement
Date and shall continue for the Term, unless earlier terminated as provided
herein, provided that if Tenant, with Landlord's prior permission, occupies or
takes possession of the Premises (or any part thereof) prior to the Lease
Commencement Date (for the installation of Tenant's furniture), then such
occupancy or possession shall be on all of the terms and conditions of this
Lease, but such occupancy or possession shall not affect the Lease Commencement
Date or the Term of this Lease.

                  3.2. POSSESSION. On or prior to October 1, 2001, Landlord
shall deliver to Tenant possession of the Premises. If the Premises are not
ready for occupancy on or prior to


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October 1, 2001, this Lease shall nevertheless continue in effect, but (a) the
Lease Commencement Date shall be delayed until the date the Premises are ready
for occupancy, (b) the Lease Expiration Date shall be delayed one (1) day for
each day after October 1, 2001, that the Premises are not ready for occupancy,
and (c) the Rent Commencement Date shall be delayed one (1) day for each day
after October 1, 2001, that the Premises are not ready for occupancy, and
Landlord shall have no other liability whatsoever on account thereof. Neither
the Lease Commencement Date nor the Rent Commencement Date shall be delayed if
the Premises are not ready for occupancy because of any delay resulting from
Tenant's failure to submit the Preliminary Space Plan within the time period
provided in Exhibit C or Tenant's failure to submit plans on or prior to
Tenant's CD Submittal Date in accordance with Exhibit C or Tenant's failure
otherwise to comply with the Approval Procedures or Tenant's failure to comply
with Landlord's Payment Request within the time period provided in Exhibit C, or
resulting from changes or additions to Tenant's plans after the initial
submission (collectively, "Tenant Delays"). Furthermore, the Rent Commencement
Date shall not be delayed in the event the schedule for completion of the
improvements to the Premises, as determined by the contractor, shall contemplate
a completion date after October 1, 2001, except to the extent of any delays in
the Lease Commencement Date which arise subsequent to the determination of the
adjusted Lease Commencement Date (as provided in Exhibit C), based upon the
contractor's schedule and which are not the result of a Tenant Delay. The
Premises shall be deemed ready for occupancy if only insubstantial details of
construction, decoration or mechanical adjustments to be performed by Landlord
remain to be done. The determination of Landlord's tenant finish representative
for the Building shall be final as to whether the Premises are ready for
occupancy. Tenant's taking possession of any portion of the Premises shall be
conclusive evidence that such portion of the Premises was in good order and
satisfactory condition when Tenant took possession, except as to latent defects
and damage caused by Tenant or Tenant's agents. On the date on which Tenant
takes possession of the entire Premises, the parties shall execute a Lease
Commencement Agreement in the form attached hereto as Exhibit E confirming the
Lease and Rent Commencement Dates and setting forth any incomplete items (if
any), but failure to execute such document shall not in any manner affect the
obligations of the parties hereunder. Tenant acknowledges that neither Landlord
nor any agent of Landlord has made any representation or warranty with respect
to the Premises or the Building, or with respect to the suitability of either
for the conduct of Tenant's business.

                  3.3. EARLY ACCESS TO PREMISES. Landlord shall use commercially
reasonable efforts to provide Tenant with access to the Premises for the sole
purpose of the installation of Tenant's furniture, telephone handsets and
computer equipment (excluding installation of computer and telephonic cabling,
which is to be performed by Landlord's Contractor in connection with the
construction of the Tenant Improvements) prior to the Lease Commencement Date;
provided, Tenant shall not interfere with Landlord's construction of the Tenant
Improvements in the exercise of Tenant's access rights, and Tenant may not use
the Premises during such access period for the purpose of conducting its
business. The foregoing early access shall not change the Lease Commencement
Date nor the Rent Commencement Date herein provided and the Rent or other
charges shall not accrue on account thereof, but all other provisions of this
Lease shall apply to such activities and occupancy. Landlord shall incur no
liability for any failure to provide such early access to Tenant.


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                  3.4. INTENTIONALLY OMITTED.

                  3.5. COMMON AREAS. Tenant shall have the nonexclusive right to
use, in common with other tenants in the Building and subject to the Building
Rules, the common areas in the Building. The "common areas" in the Building
shall mean such areas as are provided and maintained by Landlord from time to
time as areas for the common use by tenants or occupants of the Building,
including Tenant and Landlord.

                                   ARTICLE 4.
                                      RENT

                  4.1. RENT. Commencing on the Rent Commencement Date, Tenant
shall pay the Annual Base Rent specified in Article 1 to Landlord at the
location designated from time to time by Landlord payable in the Monthly Base
Rent Installment specified in Article 1 in advance, on, or prior to the first
day of each and every month during the Term without abatement or reduction
(except as expressly set forth in Section 7.3 and Articles 13 and 14 of this
Lease) or set off or deduction whatsoever. The rent for any partial month shall
be prorated on the basis of thirty (30) days to the month and shall be paid on
the first day of such partial period.

                  4.2. ADJUSTMENTS TO RENT. The Annual Base Rent shall be
adjusted from time to time in accordance with this section to reflect increases
in Expenses (as defined in Section 4.3) and Taxes (as defined in Section 4.4) in
accordance with this Section 4.2. The Annual Base Rent, the payments to be made
pursuant to this Section 4.2 and the rent for the Storage Space referred to in
Section 23.33 is referred to in this Lease as the "Rent". If the Expenses in any
lease year during the Term commencing on or after January 1, 2003 exceed the
Expense Stop Amount, Tenant shall pay Tenant's Proportionate Share of such
excess. If the Taxes in any lease year during the Term commencing on or after
January 1, 2003 exceed the Tax Expense Stop Amount, Tenant shall pay Tenant's
Proportionate Share of such excess. Within one hundred eighty (180) days after
the end of each calendar year (or portion thereof) during the Term, Landlord
will provide Tenant with a written notice ("Statement") setting forth Tenant's
Proportionate Share of increases in Expenses and/or Taxes over the Expense Stop
Amount or Tax Expense Stop Amount, as the case may be, together with a statement
of Expenses and Taxes for the previous calendar year. Within thirty (30) days
following receipt of the Statement, Tenant shall pay to Landlord as additional
rent: (a) Tenant's Proportionate Share of increases in Expenses over the Expense
Stop Amount and/or Taxes over the Tax Expense Stop Amount, as the case may be,
for the previous calendar year after credit for any estimated payments which
Tenant has made pursuant to this Section 4.2; and (b) an estimate of Tenant's
Proportionate Share for the months which have elapsed in the then current
calendar year based on the previous calendar year's increase in Expenses and/or
Taxes over the applicable Expense Stop Amount and Landlord's good faith
projection of the increase in Expenses and/or Taxes over the applicable Expense
Stop Amount during the current calendar year after credit for any estimated
payments made by Tenant pursuant to this Section 4.2. Commencing with the month
following the month in which the Statement is dated and continuing until such
time as Tenant receives Landlord's next Statement, Tenant shall, each month, pay
one-twelfth (1/12) of the estimate of Tenant's Proportionate Share of Expenses
and/or Taxes over the applicable Expense Stop Amount, which estimate shall be
based on Expenses for the previous year and taxes in excess of the Tax Expense
Stop Amount


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based on Taxes for the previous year and Landlord's good faith projection of the
increase in Expenses and Taxes for the current calendar year. Payments relative
to Expenses shall be credited against the actual Expenses as shown in Landlord's
next Statement. Similarly, payments relative to Taxes shall be credited against
the actual Taxes as shown in Landlord's next Statement. If Landlord's Statement
shows that Tenant has overpaid and if Tenant is not then in default or
thereafter in the event such default is cured within the applicable cure period,
Landlord shall credit such overpayment against the next accruing payments of
Rent until the overpayment is reduced to zero, or if the Term of this Lease
(including any Extension Period) has ended, Landlord shall repay such amount to
Tenant within thirty (30) days after the actual Expenses and Taxes are known.
The obligation to pay Tenant's Proportionate Share of the excess of Taxes and/or
Expenses over the applicable Expense Stop Amount shall survive any termination
of the Term, as extended at Tenant's option under Article 26 hereof.
Notwithstanding anything contained in this Section 4.2, the Annual Base Rent
payable by Tenant shall in no event at any time be less than the Annual Base
Rent specified in Article 1 hereof. The adjustment to Annual Base Rent payable
under this section shall be payable in respect of all periods during the Term,
including any portion of the Term prior to the Rent Commencement Date.

                  4.3. EXPENSES. The term "Expenses" means all expenses and
costs of operating the Building, including, without limitation, the following
costs: (a) wages of all employees (including employment taxes and fringe
benefits); (b) janitorial labor and materials; (c) costs of building security
personnel; (d) electricity, gas, sewer, water, trash disposal and other
utilities, but excluding those charges for which Landlord is otherwise
reimbursed by Tenant and excluding those charges separately billed to other
tenants in the Building; (e) maintenance and repairs (including maintenance and
service contracts); (f) landscaping maintenance; (g) insurance premiums; (h)
capital improvements to the extent necessary to comply with applicable
governmental rules and regulations; (i) expense of building management fees; and
(j) capital expenses which reduce any component cost of Expenses (such cost to
be reasonably amortized by Landlord and Expenses to include only the cost as so
amortized by Landlord during the calendar year for which such computation is
made). Expenses shall not include: (k) costs of alterations of any tenant's
premises; (l) principal and interest payments on loans made on the security of
the Building; (m) costs of capital expenditures (except as provided above in the
this section); and (n) leasing commissions. If the Building is not fully leased
or if Landlord is not providing standard building services to all tenants during
any calendar year, actual Expenses shall be adjusted to reflect the greater of
(i) the actual percentage of occupancy of the Building (calculated on a weighted
average using the average monthly occupancy for each month of the calendar year)
or (ii) ninety-five percent (95%) occupied; for the purpose of making the
adjustment to Annual Base Rent. Landlord shall utilize consistently applied
accounting practices in calculating Expenses during the Term.

                  4.4. TAXES. The term "Taxes" means (a) real estate taxes
assessed on the Building and personal property taxes assessed on the personal
property and equipment owned or leased by the Landlord and used in connection
with the Building, including any increases in real estate taxes as any partial
or full tax relief which presently may be afforded to the Building (either to
the Real Estate or to the facilities and improvements thereon) expires, and
further including any tax imposed as a substitute for or supplement to presently
existing real estate and/or personal property taxes; (b) reasonable expenses of
Landlord in attempting to reduce or


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<PAGE>   12

limit real estate and/or personal property taxes (any refunds to be credited
against taxes in the year received); and (c) any and all taxes, charges, an/or
surcharges payable by Landlord (other than tax on net income) whether or not now
customary or within the contemplation of the parties hereto (i) upon allocation
to, or measured by the rentable square footage of the Premises or on the rent
payable hereunder, including without limitation any gross income tax or excise
tax levied by the State, any political subdivision thereof, City or Federal
Government with respect to such rent; or (ii) upon or with respect to
possession, leasing, operation, management, maintenance, alteration, repair, use
or occupancy by Tenant of the Premises or any portion thereof.

                  4.5. INSPECTION RIGHTS. During the Term and upon ten (10) days
prior written notice to Landlord, Tenant or Tenant's designee shall have the
right, during normal business hours, to inspect at the Landlord's office in the
Building, Landlord's books and records with respect to Expenses and Taxes within
sixty (60) days of Tenant's receipt of the Statement. Landlord shall cooperate
with Tenant in any such examination of Landlord's books and records, and shall,
if requested by Tenant make available a member of its staff to explain any
entries in such books and records. Tenant may, at Tenant's expense, make copies
of any such books or records not designated as confidential by Landlord;
provided, however, that such materials may not be disclosed by Tenant to any
other person or entity without Landlord's consent. Unless Tenant asserts
specific error(s) within ninety (90) days of Tenant's receipt of the Statement,
the Statement shall be deemed to be correct. If Tenant's inspection reveals
specific error(s) in the Statement and if Tenant is not then in default or
thereafter in the event such default is cured within the applicable cure period,
Landlord shall credit any overpayment against the next accruing payments of Rent
until the overpayment is reduced to zero, or if the Term of this Lease
(including the Extension Period) has ended, Landlord shall repay such amount to
Tenant within thirty (30) days after Tenant's delivery of Tenant's inspection
results. Furthermore, if Tenant's inspection reveals that Expenses were
overstated in Landlord's Statement by more than five percent (5%), Landlord
shall reimburse Tenant for Tenant's reasonable expenses incurred in conducting
the inspection within thirty (30) days after Tenant's delivery of Tenant's
inspection results to Landlord.

                                   ARTICLE 5.
                              INTENTIONALLY OMITTED

                                   ARTICLE 6.
                                  PERMITTED USE

                  Tenant shall use and occupy the Premises only for the
Permitted Use. Occupancy on the First Floor, which is not fully occupied by
Tenant, shall not exceed one (1) person per 200 rentable square feet. The
parties hereby stipulate that Tenant shall be deemed to occupy fully the Second,
Third, Fourth and Eleventh Floors, the load capacity for which shall be subject
to Landlord's approval of Tenant's Space Plan pursuant to the Approval
Procedures set forth in Exhibit C hereto, Building floor loads and applicable
governmental regulations. Tenant and all persons permitted by Tenant to come
upon the Premises or the Storage Area shall comply with the Building Rules and
with such reasonable modifications thereof as Landlord may make from time to
time. Landlord shall not be liable for any nonobservance of the Building Rules
or the Meeting Room Rules by any other person; provided, however, that Landlord
will use reasonable


                                       9
<PAGE>   13

efforts to enforce the Building Rules and the Meeting Room Rules in a
nondiscriminatory manner. Tenant shall not make or permit to be made any use of
the Premises or the Storage Area which directly or indirectly is forbidden by
applicable law or governmental regulation or which may be dangerous to persons
or property or which may be in conflict with or invalidate or increase the
premium cost of any policy of insurance carried on the Building. To the best of
Landlord's knowledge, Tenant's permitted use of the Premises does not conflict
with or invalidate or increase the premium cost of any policy of insurance
carried on the Building. Tenant shall have the right, in common with other
tenants and occupants of the Building, to use the meeting room facilities, if
any, maintained by Landlord on the second floor of the Building as depicted on
Exhibit M to this Lease (the "Meeting Rooms"). Tenant shall comply with the
Meeting Room Rules and with such reasonable modifications thereof as Landlord
may make from time to time. The configuration and availability of the Meeting
Rooms shall be subject to such modifications as Landlord may effect at any time
and from time to time.

                                   ARTICLE 7.
                                    SERVICES

                    7.1. BUILDING STANDARD SERVICES. Landlord at Landlord's
expense shall furnish: (a) heat and air conditioning and ventilation to provide
a seasonable temperature (subject to governmental regulations) for normal
occupancy and use of the Premises under normal business operations daily from
7:30 A.M. to 7:00 P.M., Saturdays from 8:00 A.M. to 2:00 P.M., Sundays and the
following holidays excepted: New Year's Day, Memorial Day, Independence Day,
Labor Day, Thanksgiving Day and Christmas Day ("Normal Business Hours"); (b)
cold water from the public supply for drinking, lavatory and toilet purposes and
hot water for lavatory purposes from regular Building supply drawn through
fixtures installed by Landlord; (c) janitor service and customary cleaning in
and about the Premises (private kitchens, private eating areas and private
restrooms excepted) Monday through Friday (holidays excepted) comparable to
standard janitor service furnished by other comparable St. Louis office
buildings (Tenant shall not provide any janitor services or cleaning without
Landlord's prior consent, which consent shall not be unreasonably withheld or
delayed); (d) passenger elevator service in common with other tenants at all
times, subject to temporary interruptions for maintenance and subject to
interruptions in the event of emergencies (freight elevator service will be made
available by Landlord upon reasonable notice by Tenant); (e) window washing of
all exterior windows in the Premises, both inside and out, at reasonable
intervals; (f) electrical service at those points of connection provided and
installed by Landlord and in the manner and to the extent deemed by Landlord to
be standard (which standard is described as "normal electrical consumption" in
Section 7.2 below); (g) restrooms; and (h) access to telephone and network
calling at no charge to Landlord. Tenant shall have no right of access to and
within the Building for the installation or operation of systems for the
provision of electrical service to the Premises for part or all of Tenant's
electrical energy requirements without Landlord's prior written consent. Tenant
shall report to Landlord any deficiency in the services provided by Landlord or
Landlord's agents.

                  7.2. OVER BUILDING STANDARD SERVICES. If Tenant occupies the
Premises after Normal Business Hours, Tenant shall reimburse Landlord for the
increased expenses of providing utilities and other services necessary to
operate the Building during such hours, including but not limited to, increased
expenses for heating, air conditioning, security service,


                                       10
<PAGE>   14

Building employees' overtime and any unusual janitorial service. After Normal
Business Hours heating, ventilating and air conditioning will be available to
Tenant at Tenant's expense at the from time to time cost thereof to Landlord as
calculated by Landlord (which is currently $25.00 per hour per floor, but which
charge is subject to unilateral change by Landlord from time to time as provided
herein). Normal electrical consumption on the Premises is as follows: (i)
electricity drawn from Building standard receptacles: 2.5 watts per usable
square foot in the Premises per hour; (ii) Building standard lighting: 2.5 watts
per usable square foot in the Premises per hour; and (iii) Building standard
heating, ventilating and air conditioning is designed to offset 4.5 watts per
usable square foot in the Premises per hour. Tenant will not be allowed to
exceed any of the amounts of electricity in the Premises as herein referenced
without Landlord's prior written approval, which approval shall not be
unreasonably withheld. If Tenant receives Landlord's written approval, Tenant is
responsible for all expenses associated with such excess electrical consumption.
Landlord reserves the right to install submeters or to conduct an electric
consumption audit to determine electrical consumption on the Premises at the
expense of Landlord. A master meter if desired by Tenant may be installed at
Tenant's expense in a manner approved by Landlord. Landlord shall have access to
such metering devices at all reasonable times and shall prepare a separate
monthly statement of the excess utilities used by such equipment based on the
utility rates established from time to time by the public utility furnishing
such service. Tenant shall pay the amounts shown on such statements to Landlord
within thirty (30) days of receipt. Should Tenant fail to promptly pay for such
service after expiration of any applicable notice and cure periods, Landlord may
discontinue furnishing such service, which shall not be deemed an eviction
(actual or constructive) or a disturbance of Tenant's possession, use and quiet
enjoyment of the Premises. Tenant agrees that Landlord shall not be liable for
damages resulting from such discontinuance, nor shall Tenant be relieved from
the performance of any of Tenant's covenants or obligations under this Lease.
Landlord, by furnishing any of the above services, shall not be deemed to have
warranted the same to be free from any interruption or discontinuance that is
beyond the reasonable control of the Landlord or which may result from
occasional damage or malfunctions of equipment and distribution facilities. Any
such interruption or discontinuance shall not constitute an eviction (actual or
constructive) or a disturbance of Tenant's possession, use or quiet enjoyment of
the Premises. Tenant agrees that Landlord shall not be liable for damages
resulting from any such interruption or discontinuance, nor shall Tenant be
relieved of the performance of any of Tenant's covenants or obligations under
this Lease.

                  7.3. INTERRUPTION OF SERVICES. Notwithstanding the foregoing,
if (i) Landlord ceases to furnish any service in the Building for a period in
excess of five (5) consecutive days, (ii) such cessation does not arise as a
result of an act or omission of Tenant, (iii) such cessation is not caused by a
fire or other casualty, and (iv) as a result of such cessation, the Premises or
a material portion thereof is rendered untenantable (meaning that Tenant is
unable to use the Premises in the normal course of its business) and Tenant in
fact ceases to use the Premises, or a material portion thereof, then Tenant, as
its sole remedy, shall be entitled to receive an abatement of Base Rent payable
hereunder during the period beginning on the sixth (6th) consecutive day of such
cessation and ending on the day when the service in question has been restored.
In the event the entire Premises has not been rendered untenantable by the
cessation in service, the amount of abatement that Tenant is entitled to receive
shall be prorated based upon the percentage of the


                                       11
<PAGE>   15

Premises so rendered untenantable and not used by Tenant. In the event of any
cessation of any Building standard services furnished by a person or entity
other than Landlord, Landlord shall cooperate with Tenant to effect the
restoration of such Building standard services; provided that in no event shall
said cooperation require Landlord to incur any additional expense or to waive or
modify any legal rights.

                                   ARTICLE 8.
                            SUBLETTING AND ASSIGNMENT

                  8.1. SUBLEASING AND ASSIGNMENT. Tenant shall not by operation
of law or otherwise, without Landlord's prior written consent (not to be
unreasonably withheld or delayed), have the right to assign, hypothecate,
mortgage, encumber or convey this Lease or any interest in or under it, or to
sublet, or otherwise permit occupancy by any other person or entity of all or
any portion of the Premises or the Storage Area. For the purposes of this
section any transfer of stock in a corporate tenant or any transfer of an
interest in a partnership tenant in which a transfer of control of the
corporation or partnership is effected shall not be deemed to be an assignment
of this Lease requiring the prior written consent of Landlord. Any document
purporting to sublet the Premises and/or the Storage Area or assign Tenant's
interest in this Lease shall be of no force or effect unless the same shall bear
the written consent of Landlord. No subtenant or assignee shall use the Premises
for any purpose other than the Permitted Use. No permitted sublease or
assignment shall in any way release Tenant from Tenant's primary liability under
this Lease. If Tenant desires the consent of Landlord to sublease or assign, at
least thirty (30) but no more than one hundred twenty (120) days prior to the
date on which Tenant desires the assignment or sublease to be effective (the
"Transfer Date") Tenant must submit the proposed sublease or assignment to
Landlord for Landlord's approval, together with the following documents: (a) a
detailed description of the portion of the Premises and/or the Storage Area
proposed to be sublet (which must be a single, self-contained unit (the
"Space"); (b) complete copies of the financial statements of the subtenant or
assignee made available to Tenant with an authorization to verify the same; and
(c) a declaration by the subtenant or assignee as to the type of business to be
carried out. If Landlord approves the proposed sublease or assignment, within
thirty (30) days after Landlord's consent, Tenant shall submit to Landlord
executed lease estoppel certificates from Tenant and the subtenant or assignee
in the Building standard form and proof of payment of all leasing commissions,
if applicable. If Tenant is permitted to sublease at a base rent in excess of
that provided for herein, or if Tenant is permitted to assign its interest in
this Lease for any consideration whatsoever, fifty percent (50%) of such excess
or such consideration actually received (net of any subletting or assignment
costs, including, without limitation, commissions, paid by Tenant and approved
in writing by Landlord in connection with such permission to sublease or assign
and any tenant improvement costs paid by Tenant) shall be paid by Tenant to
Landlord as received. Tenant shall pay all of Landlord's out-of-pocket costs and
expenses, including reasonable attorneys' fees, relating to any such proposed
assignment or subletting.

                  8.2. SUBLEASING AND ASSIGNMENT TO AFFILIATES. Notwithstanding
the provisions of Section 8.1 of this Lease, Tenant, upon at least ten (10) days
prior written notice to Landlord (accompanied by copies of the assignment or
subletting documentation), shall be permitted to assign this Lease or to sublet
the whole or any part of the Premises to a parent,


                                       12
<PAGE>   16

wholly owned subsidiary or an affiliate of Tenant or to an entity with which
Tenant may merge or consolidate, but without the necessity of obtaining
Landlord's consent.

                                   ARTICLE 9.
                       QUIET POSSESSION AND SUBORDINATION

                  Landlord covenants and agrees with Tenant that so long as
Tenant is not in default hereunder beyond any applicable cure period, Tenant
shall peaceably and quietly enjoy the Premises through the Term without
hindrance or molestation by anyone claiming through or under Landlord, subject,
however, to the terms of this Lease. This Lease is subject and subordinate to
all present and future easements, conditions and encumbrances of record, and to
all applicable laws, ordinances and governmental rules and regulations
(hereinafter, collectively called the "Conditions"). Landlord shall obtain from
the current holder of any deeds of trust or mortgages affecting the Building a
subordination, attornment and non-disturbance agreement substantially in the
form of Exhibit I attached hereto and incorporated herein by reference and shall
use its reasonable efforts to obtain the same from the holder of any future
deeds of trust or mortgages affecting the Building. Such subordination,
attornment and non-disturbance agreement shall provide that, so long as Tenant
is not in default under this Lease beyond any applicable cure period, Tenant's
use and enjoyment of the Premises in accordance with all the material terms of
this Lease shall not be disturbed by reason of any foreclosure of any first deed
of trust. If Tenant is not furnished with such subordination, attornment and
non-disturbance agreement from the holder of any deed of trust or mortgage
hereafter affecting the Building or leasehold thereof, this Lease shall not be
subordinate to such deed of trust or mortgage and Landlord shall not be liable
to Tenant for any failure to deliver the requested subordination, attornment and
non-disturbance agreement. If Landlord obtains and delivers the required
subordination, attornment and non-disturbance agreement, the rights of Tenant
under this Lease shall be and are subject and subordinate at all times to the
lien of any deed of trust or mortgage hereafter in force against the Building,
and to all advances made or hereafter to be made upon the security thereof, and
to all renewals, modifications, consolidations, replacements and extensions
thereof. Except as expressly set forth above, this Article 9 is self-operative
and no further instrument of subordination shall be required. In confirmation of
such subordination Tenant shall promptly execute the required subordination,
attornment and non-disturbance agreement and any and all such further
instruments as may be reasonably requested by Landlord. If any purchaser at a
foreclosure sale (or by deed in lieu of foreclosure) becomes the owner of the
Premises, Tenant will attorn to and recognize such entity's becoming such owner
for all purposes in place of the Landlord named in this Lease; provided that
there shall be no credit given by such entity to Tenant for any Rent which has
been prepaid more than one (1) month in advance.

                                   ARTICLE 10.
                           LANDLORD'S RESERVED RIGHTS

                  Landlord reserves the following rights: (a) to change the
street address of the Building; (b) to maintain one or more signs on the
exterior of the Building; (c) to designate and control all sources furnishing
Building related services to tenants; (d) at any time during the Term (if Tenant
has vacated the Premises) and otherwise during the last six (6) months of the
Term, to display "for rent" signs on and exhibit and otherwise prepare the
Premises for


                                       13
<PAGE>   17

reoccupancy; (e) to retain passkeys to all doors within and into the Premises;
(f) during the last six (6) months of the Term to exhibit the Premises to
prospective lessees upon reasonable notice to Tenant; (g) to grant to anyone the
exclusive right to conduct any particular business in the Building; (h) to close
the Building after Normal Business Hours and on legal holidays and to affect
such reasonable security measures as Landlord may deem appropriate and in the
best interests of the Building and tenants; subject, however, to Tenant's right
to admittance on a 24 hour basis, seven days per week under such reasonable
security regulations as Landlord may prescribe from time to time; (i) to approve
the weight, size, and location of safes or other heavy objects, which objects
may be moved in, about or out of the Building or Premises and/or the Storage
Area only at such times and in such manner as Landlord shall direct, and in all
events at Tenant's sole risk and responsibility; and (j) to take any and all
measures necessary or desirable for the operation, safety, protection or
preservation of the Building, including repairs, alterations, decorations,
additions or improvements, whether structural or otherwise, in and about the
Building or any part thereof, and installation of an energy management system to
more accurately monitor and control heat, ventilating and air conditioning in
the Building, and during the continuance of any such work to temporarily close
doors, entry ways, public spaces and corridors in the Building and to interrupt
or temporarily suspend Building services or facilities upon reasonable prior
notice to Tenant, except in the event of emergency. Landlord may enter upon the
Premises upon reasonable notice to Tenant (except in the case of an emergency)
and may exercise any or all of the foregoing rights without being deemed guilty
of an eviction (actual or constructive) or disturbance of Tenant's use or
possession and without being liable in any manner to Tenant and without
abatement of rent or affecting of Tenant's obligations hereunder. Landlord shall
comply with applicable laws, rules and regulations and the Building Rules and
the Meeting Room Rules in connection with the operation, maintenance and
management of the Building.

                                   ARTICLE 11.
                          ALTERATIONS AND IMPROVEMENTS

                  Tenant shall not, without the prior written consent of
Landlord, which consent shall not be unreasonably withheld or delayed, make any
alterations, improvements or additions to the Premises and/or the Storage Area
(hereinafter referred to as a "Change"). Tenant's reconfiguration of its office
units shall not require Landlord's consent unless such reconfiguration results
in alterations to the Building's HVAC, electrical, plumbing or other utility
system. If Landlord consents to a Change it may impose such conditions with
respect thereto as Landlord, acting in its reasonable discretion, deems
appropriate, including without limitation, requiring Tenant to furnish Landlord
security for the payment of all costs to be incurred in connection with the
Change, insurance against liabilities which may arise out of such work and the
plans and specifications naming Landlord as an additional insured together with
all necessary permits for such Change. The work necessary to make the Change
shall be done at Tenant's expense by employees or contractors selected by Tenant
and, with respect to a Change, approved by Landlord, which approval shall not be
unreasonably withheld or delayed, and shall be performed in such manner and at
such times as Landlord shall direct to minimize disturbance to other tenants
(and without limiting the generality of the foregoing, Tenant acknowledges that
Landlord may withhold its consent to the use of employees or contractors
selected by Tenant if, in Landlord's judgment, the retention of such employees
or contractor might delay, hinder or


                                       14
<PAGE>   18

otherwise interfere with Landlord's construction activities in or management of
the Building. Tenant shall promptly pay, when due, the cost of all such work and
of all decorating required by reason thereof. Tenant shall also pay to Landlord
a percentage of the cost of such work (such percentage to be established on a
uniform basis for the Building by Landlord from time to time) but not to exceed
as to Landlord's fee, five percent (5%) of such construction costs sufficient to
reimburse Landlord for all expenses arising from Landlord's involvement with
such work. Upon completion of such work, Tenant shall deliver to Landlord, if
payment is made directly to contractors, evidence of payment, contractors'
affidavits and full and final waivers of all liens for labor, services or
materials (in the form attached hereto as Exhibit F). Tenant shall defend and
hold Landlord and the Building harmless from all costs, damages and liens and
expenses related to such work. In connection with such work Tenant shall never
be deemed an agent of Landlord. All work done by Tenant or Tenant's contractors
shall be done in a first class workmanlike manner using only good grades of
materials and shall comply with all union and insurance requirements and all
Conditions. In consideration of Landlord's consent to such Change, any Change
shall (without further compensation to Tenant) become Landlord's property at the
termination of the Term, and shall, unless Landlord requests otherwise (at the
time consent is given or notice is received by Landlord), be relinquished to
Landlord in good condition, ordinary wear, casualty, condemnation and damage due
to acts or omissions of Landlord, its agents, engineers or contractors excepted.

                                   ARTICLE 12.
                            REPAIRS AND REPLACEMENTS

                  Landlord, at Landlord's expense, shall maintain and keep in
good condition the Premises, the Storage Area, and Building including the
foundation, exterior walls, roof, roof membrane and roof covering of the
Building, sprinkler systems in or serving the Premises and/or the Building, HVAC
system, and plumbing, electric and other utility lines servicing the Building or
connecting the Premises, the Storage Area, and the Building, except for damage
to the Premises, the Storage Area, and Building (including the parts thereof
specified above) caused by acts or omissions of Tenant, Tenant's agents,
employees, contractors, guests or invitees, in which event Tenant, subject to
the provisions of Section 19.2 hereof, will bear the cost of such maintenance or
repair. Tenant, at Tenant's expense, shall at all times keep the Premises and
the Storage Area in a clean, safe and tenantable condition and in first class
order, repair and appearance and Landlord shall have the right to approve the
means and methods employed in performance of such work. If Tenant does not do so
Landlord may (but need not), after the notice and cure periods specified in
Section 17.1, restore the Premises and the Storage Area to a clean, safe and
tenantable condition, and Tenant shall pay the cost thereof forthwith upon being
billed by Landlord. This Section shall not apply to damage or destruction and
condemnation proceedings otherwise provided for in this Lease. In the event
emergency repairs are required within the Premises and Tenant is unable to
contact Landlord after diligent and persistent efforts so to do and Landlord is
otherwise unaware of such emergency, Tenant may perform Landlord's repair
obligations within the Premises as set forth herein. Such repairs shall be
performed in a good and workmanlike manner using materials of a quality
comparable to the materials used in the construction of the Premises and the
Building generally. During the performance of such repairs (and thereafter,
until Tenant is able to contact Landlord), Tenant shall endeavor to notify
Landlord that Tenant has undertaken to make such repairs on Landlord's behalf
and Landlord


                                       15
<PAGE>   19

shall have the right to assume the performance of such repairs at any time. Any
such repairs undertaken by Tenant shall be performed in a manner so as not to
interfere with any other tenant's access to or use and occupancy of its premises
within the Building. Landlord shall reimburse Tenant for the reasonable costs of
said repairs within thirty (30) days of Landlord's receipt of an invoice for
same. For the purposes of this Article 12, an "emergency" necessitating such
repairs shall not be deemed to exist unless Tenant reasonably determines that
there is an imminent threat of harm to any person or an imminent threat of
material damage to Tenant's property located in the Premises.

                                   ARTICLE 13.
                              DESTRUCTION OR DAMAGE

                  If all or a substantial portion of the Premises be rendered
untenantable, inaccessible or unsafe by fire or other casualty, or portions of
the Building, exclusive of the Premises are damaged or a system therein is
damaged in such a way as to render the Premises untenantable by fire or other
casualty and if it is reasonably anticipated that even though undertaken and
pursued with all due diligence it will require more than six (6) months to
repair the damaged area, or if the Building or Premises are damaged by an
uninsured casualty (meaning a casualty which would not have been covered by
standard "all risk" insurance coverage, determined as of the date of this
Lease), (i) Landlord may terminate this Lease as of the date of such casualty by
notice to Tenant given within thirty (30) days after such occurrence, and (ii)
if such casualty occurs during the last twelve (12) months of the Term and is
not caused by any willful act or omission of Tenant, Tenant may terminate this
Lease as of the date of such casualty by notice to Landlord given within thirty
(30) days after such occurrence. If neither Landlord nor Tenant elects to
terminate this Lease, Landlord shall proceed with all due diligence to repair
the damaged area at Landlord's expense and the Rent shall abate as to that
portion of the Premises which is untenantable for so long as the same shall
remain untenantable. If this Lease is terminated pursuant to this section, Rent
shall be apportioned on a per diem basis and paid to the date of the casualty.
If the Premises are partially damaged by fire or other casualty but are not
rendered substantially untenantable, then Landlord shall proceed with all due
diligence to repair the Premises and the Rent shall abate as to that portion of
the Premises which is untenantable for so long as the same shall remain
untenantable, but Rent shall not otherwise abate. If all or a substantial
portion of the St. Louis Centre Garage shall be rendered untenantable,
inaccessible or unsafe by fire or other casualty, Tenant's obligation to pay
parking charges for the parking spaces in the St. Louis Centre Garage shall
abate for so long as the same shall remain untenantable, inaccessible or unsafe,
as the case may be.

                                   ARTICLE 14.
                                 EMINENT DOMAIN

                  If the whole of the Building or the whole of the Premises
shall be taken by the exercise of the power of eminent domain or pursuant to any
agreement in lieu of the exercise of such power (hereinafter called a
"Condemnation Proceeding"), then this Lease shall terminate as of the date of
the taking of possession by or the vesting of title in the condemning authority
(such date being hereinafter called the "Taking Date"). If less than the whole
of the Building or less than the whole of the Premises shall be taken in a
Condemnation Proceeding, Tenant may at


                                       16
<PAGE>   20

Tenant's option terminate this Lease as of the Taking Date by giving notice of
Tenant's exercise of such option within sixty (60) days after the Taking Date,
provided that as a result of such taking Landlord shall have reasonably
determined that the Premises (or the remaining portion thereof) may no longer be
adequately used for the Permitted Use. If a portion of the Premises shall be
taken and Tenant shall not exercise Tenant's option to terminate this Lease or
if such taking shall not give rise to such option to terminate, then this Lease
shall terminate on the Taking Date only as to that portion of the Premises so
taken but shall remain in full force and effect with respect to that portion of
the Premises not so taken, and the Rent and other charges payable by Tenant
hereunder shall be reduced in the ratio in which the diminution of the rentable
square footage of the Premises following the Taking Date shall bear to the
rentable square footage thereof immediately prior to such Taking Date. Except as
otherwise ordered by the court in a Condemnation Proceeding, all income, rent,
awards or interest derived from any Condemnation Proceeding shall belong to and
be the property of Landlord, but this shall not preclude Tenant from making an
independent claim for the value of Tenant's personal property which Tenant is
entitled to remove under this Lease in such Condemnation Proceeding and Tenant's
relocation expenses provided that such claim does not result in a reduction of
Landlord's award.

                                   ARTICLE 15.
                                  HOLDING OVER

                  If Tenant without the consent of Landlord retains possession
of the Premises, the Storage Area, or any part thereof after termination of the
Term, Tenant shall pay to Landlord Rent (i) for the first sixty (60) days (or
portion thereof) of such holding over at a rate equal to one hundred fifty
percent (150%) of the Rent payable for the month immediately preceding the
commencement of said holding over and (ii) thereafter at a rate equal to two
hundred percent (200%) of the Rent payable for the month immediately preceding
the commencement of said holding over, all as computed on a per month basis for
each month or part thereof (without reduction for any partial month) that Tenant
remains in possession, and in addition thereto, Tenant shall pay Landlord all
direct and consequential damages sustained by reason of Tenant's retention of
possession. Any such retention of possession shall constitute a month to month
lease terminable in accordance with law.

                                   ARTICLE 16.
                             SURRENDER OF POSSESSION

                  Upon the termination of the Term Tenant shall immediately
surrender the Premises and the Storage Area (together with any Changes) to
Landlord in good order, repair and condition, ordinary wear and casualty losses
for which Tenant is not responsible pursuant to the terms of this Lease and
damage caused by acts or omissions of Landlord, its agents, contractors or
employees excepted, and shall remove all office furniture and equipment, trade
fixtures and other items of Tenant's property on the Premises and the Storage
Area. Tenant shall pay Landlord upon demand the reasonable cost of repairing any
damage to the Premises, the Storage Area, and to the Building not repaired by
Tenant and caused by any such removal. If Tenant fails or refuses to remove any
such property from the Premises, the Storage Area or the Building,


                                       17
<PAGE>   21

Tenant shall be conclusively presumed to have abandoned the same and Landlord
may dispose of the same without incurring any liability therefor.

                                   ARTICLE 17.
                              DEFAULT AND REMEDIES

                  17.1. TENANT DEFAULTS AND LANDLORD'S REMEDIES. If Tenant shall
default in the payment of any installment of the Rent or in the payment of any
other sum required to be paid by Tenant under this Lease and such default shall
continue for ten (10) days after written notice to Tenant, or if Tenant shall
default in the observance or performance of any other covenant or condition in
this Lease which Tenant is required to observe or perform and such default shall
continue for thirty (30) days after written notice to Tenant (or, in the event
Landlord determines, in its reasonable judgment, that (i) such default is
capable of cure by Tenant and such default will not cause or contribute to a
breach or default under any mortgage lien on the Building, (ii) Tenant commences
the cure of such default within the foregoing thirty (30) day period, and (iii)
Tenant diligently prosecutes the complete cure of such default in good faith,
then such longer period as may be reasonably necessary to effect such cure), or
if a default involves a hazardous condition and is not cured by Tenant
immediately upon written notice to Tenant, or if the interest of Tenant in this
Lease shall be levied upon under execution or other legal process, or if any
voluntary petition in bankruptcy or for corporate reorganization or any similar
relief shall be filed by Tenant, or if any involuntary petition in bankruptcy
shall be filed against Tenant under any federal or state bankruptcy or
insolvency act and shall not have been dismissed within sixty (60) days
following the filing thereof, or if a receiver shall be appointed for Tenant or
any of the property of Tenant by any court and such receiver shall not be
dismissed within sixty (60) days from the date of appointment, or if Tenant
shall make an assignment for the benefit of creditors, or if Tenant shall admit
in writing Tenant's inability to meet Tenant's debts as they mature, then
Landlord may treat the occurrence of any one or more of the foregoing events as
a breach of this Lease and thereupon at Landlord's option may, without notice or
demand of any kind to Tenant or any other person, exercise one or more of the
following described remedies, in addition to all other rights and remedies
provided at law or in equity:

                           (a) Landlord may terminate this Lease and the estate
                  created hereby by giving Tenant written notice of such intent,
                  in which event Landlord may forthwith repossess the Premises
                  and the Storage Area and be entitled to recover forthwith, in
                  addition to any other sums or damages for which Tenant may be
                  liable to Landlord as damages, an amount, if any, equal to the
                  Rent which would have been payable during any period of
                  rent-free occupancy provided to Tenant by this Lease, the cost
                  of all unamortized leasing commissions paid by Landlord in
                  connection with this Lease, the unamortized portion (based
                  upon the portion of the initial Term elapsed) of the cost to
                  Landlord of the initial leasehold improvements to the
                  Premises, and all other amounts paid to or on behalf of Tenant
                  in connection with Tenant's entry into this Lease and
                  occupancy of the Premises and the Storage Area (including
                  without limitation any moving cost allowance, payments on
                  lease(s) assumed by Landlord, payment for preparation of floor
                  plans and the like), including Landlord's


                                       18
<PAGE>   22

                  interest expense thereon, together with a sum of money equal
                  to the net present value of the excess of the value of the
                  Rent provided to be paid by Tenant for the balance of the Term
                  over the fair market rental value of the Premises, after
                  deduction of all anticipated expenses of reletting for said
                  period. The net present value shall be calculated using a
                  discount rate of seven percent (7%) per annum.

                           (b) Landlord may terminate Tenant's right of
                  possession and may repossess the Premises and the Storage Area
                  by forcible entry or unlawful detainer suit, by taking
                  peaceful possession or otherwise without terminating this
                  Lease, in which event Landlord may, but shall be under no
                  obligation to, relet the same for the account of Tenant, for
                  such rent and upon such terms as shall be satisfactory to
                  Landlord. For the purpose of such reletting, Landlord is
                  authorized to decorate, repair, remodel or alter the Premises.
                  If Landlord shall fail to relet the Premises, Tenant shall pay
                  to Landlord as damages a sum equal to the amount of the Rent
                  reserved in this Lease for the balance of the then-existing
                  Term of this Lease, as such Rent becomes due and payable under
                  the terms of this Lease. If the Premises are relet and a
                  sufficient sum shall not be realized from such reletting after
                  paying all of the costs and expenses of all decoration,
                  repairs, remodeling, alterations and additions and the
                  expenses of such reletting to satisfy the Rent provided for in
                  this Lease and the amounts recoverable (including broker's
                  fees) by Landlord from Tenant pursuant to subparagraph (a) of
                  this paragraph, Tenant shall satisfy and pay the same upon
                  demand therefor from time to time. Landlord may file suit to
                  recover any sums falling due from time to time and no suit or
                  recovery of any portion due Landlord hereunder shall be any
                  defense to any subsequent action brought for any amount not
                  theretofore reduced to judgment in favor of Landlord.

No waiver of any default by Tenant shall be implied from any omission by
Landlord to take any action on account of said default if such default persists
or shall be repeated, and no express waiver shall affect any default other than
the default specified in the express waiver and then only for the time and to
the extent therein stated. No failure of Landlord to exercise any power given
Landlord hereunder or to insist upon strict compliance with any obligation
hereunder and no custom or practice of the parties at variance with the terms
hereof shall constitute a waiver of Landlord's right to demand exact compliance
with the terms hereof. The provisions of this Section shall survive any
termination of this Lease. In the event of a default by Tenant under this Lease
which continues beyond any applicable cure period, Landlord shall use reasonable
good faith efforts to mitigate its damages in accordance with the laws of the
State of Missouri.

                  17.2. LANDLORD'S DEFAULTS. If Landlord shall default in the
observance or performance of any covenant or condition in this Lease which
Landlord is required to observe or perform and such default shall continue for
thirty (30) days after written notice to Landlord (or, in the event Landlord
commences the cure of such default within the


                                       19
<PAGE>   23

foregoing thirty (30) day period, and Landlord diligently prosecutes the
complete cure of such default in good faith, such longer period as may be
reasonably necessary to effect such cure), Tenant shall thereafter have the
right to perform such covenant or effect the satisfaction of such condition and
Landlord shall reimburse Tenant for Tenant's reasonable costs in connection
therewith within thirty (30) days of receipt of Tenant's invoice therefor.
Tenant may effect such performance only within the Premises and such portions of
common areas of the Building necessary for the use and occupancy of the
Premises, and further shall effect such performance without causing or
contributing to any breach or default of other leases of the Building or any
mortgage lien on the Building.

                                   ARTICLE 18.
                                   BANKRUPTCY

                  If a petition is filed by or against Tenant for relief under
the bankruptcy laws of the United States (the "Bankruptcy Code"), and Tenant
(including for the purposes of this section Tenant's successor in bankruptcy,
whether a trustee or Tenant as debtor in possession) assumes and proposes to
assign, or proposes to assume and assign, this Lease pursuant to the provisions
of the Bankruptcy Code to any person or entity who has made or accepted a bona
fide offer to accept an assignment of this Lease on the terms acceptable to
Tenant, then notice of the proposed assignment setting forth (a) the name and
address of the proposed assignee, (b) all of the terms and conditions of the
offer and proposed assignment, and (c) the adequate assurance to be furnished by
the proposed assignee of the proposed assignee's future performance under this
Lease, shall be given to Landlord by Tenant no later than twenty (20) days after
Tenant has made or received such offer, but in no event later than ten (10) days
prior to the date on which Tenant applies to a court of competent jurisdiction
for authority and approval to enter into the proposed assignment. Landlord shall
have the prior right and option, to be exercised by notice to Tenant given at
any time prior to the date on which the court order authorizing such assignment
becomes final and non-appealable, to receive an assignment of this Lease upon
the same terms and conditions, and for the same consideration, if any, as the
proposed assignee, less any brokerage commission which may otherwise be payable
out of the consideration to be paid by the proposed assignee for the assignment
of this Lease. If this Lease is assigned pursuant to the provisions of the
Bankruptcy Code, Landlord: (i) may require from the assignee a deposit or other
security for the performance of assignee's obligations under this Lease in an
amount substantially the same as would have been required by Landlord upon the
initial leasing to a tenant similar to the assignee; and (ii) shall be entitled
to receive as additional Rent, any amounts received by Tenant in connection with
such assignment. Any person or entity to which this Lease is assigned pursuant
to the provisions of the Bankruptcy Code shall be deemed without further act or
documentation to have assumed all of the Tenant's obligations arising under this
Lease on and after the date of such assignment. Any such assignee shall upon
demand execute and deliver to Landlord an instrument confirming such assumption.
No provision of this Lease shall be deemed a waiver of Landlord's rights or
remedies under the Bankruptcy Code to oppose any assumption and/or assignment of
this Lease, or to regain possession of the Premises if this Lease has neither
been assumed nor rejected within sixty (60) days after the date of the order for
relief or within such additional time as a court of competent jurisdiction may
have fixed. Notwithstanding anything in this Lease to the contrary, all amounts
payable by Tenant to or on behalf of Landlord under this


                                       20
<PAGE>   24

Lease, whether or not expressly denominated as rent, shall constitute rent for
the purposes of Section 502(b)(6) of the Bankruptcy Code.

                                   ARTICLE 19.
                        INSURANCE AND WAIVER OF RECOVERY

                  19.1. INSURANCE. Tenant shall at all times during the Term
maintain in full force and effect with respect to the Premises (a) commercial or
comprehensive general liability insurance (on an occurrence and not claims-made
basis) having the limits set forth in Article 1 hereof, (b) all risk property
insurance upon all property owned or used by Tenant in the Premises in an amount
equal to the full replacement cost thereof, (c) workers' compensation and
employer's liability insurance in form and in at least the minimum amount
required by law, (d) contractual liability insurance sufficient to cover
Tenant's indemnity obligations hereunder and (e) such other coverage as may be
reasonably required by Landlord or any mortgagee of the Building, each in the
standard form generally of use in the State of Missouri by a company reasonably
satisfactory to Landlord. The amount of such insurance coverage shall be subject
to increase upon the reasonable request of Landlord. Such insurance shall be
subject to modification, exhaustion or cancellation only upon ten (10) days
notice to Landlord. Tenant, at or prior to the Lease Commencement Date, and
thereafter not less than thirty (30) days prior to the expiration of any such
policy, shall furnish Landlord with an endorsement to all such insurance, such
endorsement to be in a form reasonably acceptable to Landlord and any mortgagee
of the Building and, at the request of Landlord, to name Landlord, and any such
mortgagee as an additional insured.

                  19.2. WAIVER OF RECOVERY. Landlord and Tenant hereby mutually
waive any and all rights of recovery against one another for real or personal
property loss or damage occurring to the Premises or to the Building or any part
thereof or any personal property located therein from perils which are able to
be insured against in standard fire and extended coverage, vandalism and
malicious mischief and sprinkler leakage insurance contracts (commonly referred
to as "All Risk") issued in the State of Missouri (whether or not such insurance
actually is carried). Such release shall include any deductible or self insured
retention. Landlord and Tenant shall request their insurance carriers to consent
to a waiver of all rights of subrogation against each other by inclusion of such
a clause in their respective policies or by endorsement thereto.

                  19.3. INDEMNITY BY TENANT. Subject to the foregoing limited
waiver, Tenant shall defend and indemnify Landlord and save Landlord harmless
from and against any and all claims against Landlord arising from (a) Tenant's
use or occupancy of the Premises or the conduct of Tenant's business or from any
activity, work or thing done, permitted or suffered by Tenant in or about the
Premises or Building, (b) the nonperformance of any covenant or agreement on
Tenant's part to be performed pursuant to the terms of this Lease (including,
without limitation, any claims arising from a breach or default under any other
lease of the Building caused by or contributed to by Tenant's default under this
Lease) or (c) any act or negligence of Tenant or of any of Tenant's agents,
contractors, employees, invitees or licensees, and from and against all costs,
counsel fees, expenses and liabilities incurred in any such claim or in any
action or proceeding brought thereon; and in case any action or proceeding be
brought


                                       21
<PAGE>   25

against Landlord by reason of any such claim, Tenant upon notice from Landlord,
covenants to resist or defend at Tenant's expense such action or proceeding by
counsel reasonably satisfactory to Landlord; provided, that the foregoing
provision shall not be construed to make Tenant responsible for loss, damage,
liability or defense resulting from injuries to third parties to the extent
caused by the negligence of Landlord or Landlord's contractors, licensees,
employees, guests and invitees.

                  19.4. INDEMNITY BY LANDLORD. Landlord shall defend and
indemnify Tenant and save Tenant harmless from and against any and all claims
against Tenant arising from (a) the nonperformance of any covenant or agreement
on Landlord's part to be performed pursuant to the terms of this Lease, or (b)
any act or negligence of Landlord or any of Landlord's agents, contractors,
employees, invitees or licensees (but not including, in any event, other tenants
of the Building and their respective agents, contractors, employees, invitees or
licensees), and from and against all costs, counsel fees, expenses and
liabilities incurred in any such claim or in any action or proceeding brought
thereon; and in case any action or proceeding be brought against Tenant by
reason of any such claim, Landlord, upon notice from Tenant, covenants to resist
or defend at Landlord's expense such action or proceeding by counsel reasonably
satisfactory to Tenant; provided that the foregoing provision shall not be
construed to make Landlord responsible for loss, damage, liability or defense
resulting from injuries to third parties to the extent caused by the negligence
of Tenant or Tenant's contractors, licensees, employees, guests and invitees. It
is expressly understood and agreed that none of Landlord's covenants,
undertakings and agreements under this Lease are made or intended as personal
covenants, undertakings or agreements by Landlord, and any liability for damage
or breach or nonperformance by Landlord shall be collectible only out of
Landlord's interest in the Building, and no personal liability is assumed by or
at any time may be asserted against Landlord.

                  19.5. LANDLORD'S INSURANCE. Landlord shall at all times
maintain in full force and effect with respect to the Building commercial or
comprehensive general liability insurance having the limits set forth in Article
1 hereof and property damage insurance with respect to the Building of a type
and in commercially reasonable amounts comparable to insurance obtained by other
similarly situated landlords.

                  19.6. TENANT'S SELF-INSURANCE; BLANKET POLICIES. Tenant may
satisfy its obligations under Section 19.1, in whole or in part, by means of
self-insurance (provided Tenant has a net worth of at least Four Hundred Million
and No/100 Dollars ($400,000,000.00), sufficient evidence of which shall be
Tenant's most recent annual report), or a so-called blanket policy. Tenant's
blanket policy permitted hereunder shall specifically allocate to the
liabilities required to be insured by Tenant under this Article an amount not
less than the amount of insurance required to be carried by Tenant under this
Article.

                                   ARTICLE 20.
                           TAXES ON TENANT'S PROPERTY

                  20.1. PERSONAL PROPERTY TAXES. Tenant shall be liable for and
shall pay before delinquency, taxes levied against any personal property or
trade fixtures placed by Tenant in the Premises. If any such taxes on Tenant's
personal property or trade fixtures are levied against


                                       22
<PAGE>   26

Landlord or Landlord's property or if the assessed value of the Building is
increased by the inclusion therein of a value placed upon such personal property
or trade fixtures of Tenant and if Landlord, after written notice to Tenant,
pays the taxes based upon such increased assessments, which Landlord shall have
the right to do regardless of the validity thereof, but only under proper
protest if requested by Tenant, Tenant shall upon demand repay to Landlord the
taxes levied against Landlord, or the proportion of such taxes resulting from
such increase in the assessment; provided that in any such event, at Tenant's
sole cost and expense, Tenant shall have the right, in the name of Landlord and
with Landlord's full cooperation, to bring suit in any court of competent
jurisdiction to recover the amount of any such taxes so paid under protest, any
amount so recovered to belong to Tenant.

                  20.2. EXCESS REAL ESTATE TAXES. If the leasehold improvements
in the Premises and/or the Storage Area, whether installed and/or paid for by
Landlord or Tenant and whether or not affixed to the real property so as to
become a part thereof, are assessed for real property tax purposes at a
valuation higher than the valuation at which leasehold improvements conforming
to Landlord's building standard work in other space in the Building are
assessed, then the real property taxes and assessments levied against Landlord
or the property by reason of such excess assessed valuation shall be deemed to
be taxes levied against personal property of Tenant and shall be governed by the
provisions of Section 20.1 above. If the records of the City Assessor are
available and sufficiently detailed to serve as a basis for determining whether
said improvements are assessed at a higher valuation than Landlord's building
standard work, such records shall be binding on both Landlord and Tenant. If the
records of the City Assessor are not available or sufficiently detailed to serve
as a basis for making said determination, the actual cost of construction shall
be used.

                                   ARTICLE 21.
                         AMERICANS WITH DISABILITIES ACT

                  Landlord shall be responsible for compliance with the
requirements of the Americans with Disabilities Act (the "ADA") with respect to
the Building shell, lobbies, restrooms (including Building Standard restrooms on
floors fully occupied by Tenant), and other common areas of the Building, and
agrees to hold Tenant harmless with respect to failure by Landlord to fulfill
Landlord's obligations under the ADA with respect to those areas. Tenant shall
be responsible for compliance with the requirements of the ADA with respect to
the Premises and the Storage Area, and the use and occupancy of the Premises and
the Storage Area by Tenant, and agrees to hold Landlord harmless with respect to
failure by Tenant to fulfill Tenant's obligations under the ADA with respect to
the occupancy and use of the Premises and the Storage Area.

                                   ARTICLE 22.
                               HAZARDOUS MATERIALS

                  The Building was constructed in compliance with the codes and
regulations in effect at the time of construction. Landlord agrees to comply
with all applicable laws and regulations relating to hazardous materials
associated with the Building structure and common areas. The foregoing does not
relate to compliance with laws or regulations which are applicable


                                       23
<PAGE>   27

to the use or occupancy of premises in the Building by individual tenants or the
conduct of such tenant's business in those premises and compliance with those
laws and regulations shall be the sole responsibility of the individual tenants.
As of the date of this Lease, to the best of Landlord's knowledge, the Premises
contain no asbestos and Landlord has received no notice with respect to the
Building from any governmental agency of any violation of the Comprehensive
Environmental Response, Compensation and Liability Act ("CERCLA"), Resource
Conservation and Recovery Act ("RCRA") or any similar law or regulation in
effect in the State of Missouri. Tenant agrees to comply with all applicable
laws and regulations relating to hazardous materials and Tenant shall not use,
store, dispose of, or generate any such materials in, on or about the Premises,
the Storage Area, or the Building, except as customarily used for general office
purposes, which materials may be utilized and subsequently disposed of only in
strict compliance with all applicable laws and regulations and insurance
requirements applicable to the Building.

                                   ARTICLE 23.
                               GENERAL PROVISIONS

                  23.1. COSTS AND EXPENSES OF ENFORCEMENT: If Tenant or Landlord
brings any action for any relief against the other, declaratory or otherwise,
arising out of this Lease, including any suit by Landlord for the recovery of
Rent or possession of the Premises and the Storage Area, the losing party shall
reimburse the prevailing party for the reasonable fees and costs of attorneys,
including the reasonable fees and costs of investigators and experts engaged in
connection with such action and reasonable fees, costs and expenses incurred in
connection with any appeal, all of which shall be deemed to have accrued on the
commencement of such action and shall be paid whether or not the action is
prosecuted to judgment. The "prevailing party" shall be the party that prevails
in obtaining a remedy or relief which most nearly reflects the remedy or relief
which that party sought.

                  23.2. LATE FEES: All amounts due Landlord under this Lease
shall be considered past due for the purposes hereof on the tenth (10th) day
after the due date and shall bear interest from such date until paid at an
annual rate equal to four percent (4%) in excess of the then publicly announced
Prime Rate of Firstar Bank, N.A., or its successor (the "Bank") which rate shall
change as and when such Prime Rate shall be changed by such Bank, or the highest
lawful rate, whichever is less. If the Bank no longer exists, then in such
event, Landlord may designate another bank doing business in the City or County
of St. Louis, Missouri to determine the Prime Rate for purposes of this section.

                  23.3. NOTICES: All notices, consents, approvals and requests
required or permitted hereunder shall be given in writing and shall be effective
for all purposes if hand delivered or sent by (a) certified or registered United
States mail, postage prepaid, or (b) expedited prepaid delivery service, either
commercial or United States Postal Service, with proof of attempted delivery,
and (c) by telecopier (with answer back acknowledged), addressed if to Landlord
at Landlord's address set forth in Article 1 hereof, or at such other address
designated from time to time by Landlord, or if to Tenant, at Tenant's address
set forth in Article 1 hereof, or at such other address designated from time to
time by Tenant. A notice shall be deemed to have been given: in the case of hand
delivery, at the time of delivery; in the case of registered or


                                       24
<PAGE>   28

certified mail, when delivered or the first attempted delivery on a Business
Day; or in the case of expedited prepaid delivery and telecopy, upon the first
attempted delivery on a Business Day. The copy of the notice delivered to
Tenant's counsel shall be a courtesy copy only, and the failure to provide such
courtesy copy shall have absolutely no effect or entitle Tenant to any remedy
whatsoever. In no event shall Landlord's failure to deliver such courtesy copy
affect the validity of any notice to Tenant, which notice shall be effective
whether or not the courtesy copy was given to Tenant's counsel.

                  23.4. LANDLORD'S RIGHT TO TRANSFER INTEREST: Landlord has the
right to transfer Landlord's interest in the Building and in this Lease, and
upon any such transfer, and in the event such transfer occurs prior to
Landlord's substantial completion of the Tenant Improvements, upon such
transferee's written assumption of Landlord's obligations hereunder, Landlord
shall automatically be released from all liability accruing under this Lease
after the date of such transfer, and Tenant shall look solely to such transferee
for the performance of Landlord's obligations hereunder, Landlord's (and such
transferee's) liability in any event to be without personal liability or
recourse to any assets other than Landlord's or such transferee's interest and
title in and to the Building. Landlord may assign Landlord's interest in this
Lease to a mortgage lender as additional security provided that such assignment
shall not release Landlord from Landlord's obligations hereunder and Tenant
shall continue to look solely to Landlord for the performance of Landlord's
obligations hereunder.

                  23.5. ENTIRE AGREEMENT: This Lease, together with the Exhibits
referenced in Article 1 and Addendum(s), if any, constitutes the entire
agreement between the parties with respect to the subject matter hereof, and
shall be binding upon the parties hereto and their respective heirs, personal
representatives, executors, successors and permitted assigns, as the case may
be. All terms used in this Lease shall be deemed to refer to the masculine,
feminine, neuter, singular or plural, as the context may require.

                  23.6. APPLICABLE LAW AND PARTIAL INVALIDITY: This Lease shall
be governed by and enforced in accordance with the laws of the State of
Missouri. The invalidity or unenforceability of any provision of this Lease
shall not affect or impair any other provision.

                  23.7. AMENDMENT: This Lease may not be altered, amended,
modified, or extended except by written instrument signed by Landlord and
Tenant.

                  23.8. WAIVER: The waiver by either Landlord or Tenant of any
breach of any term, condition or covenant of this Lease shall not be deemed to
be a waiver of any subsequent breach of the same or any other term, condition or
covenant of this Lease. No failure either by Landlord or Tenant to take action
against the other party hereto on account of any failure by such party to
perform any of such party's obligations under this Lease shall be deemed to be a
waiver by the non-defaulting party, except only where the non-defaulting party
has provided the other party a written waiver, signed by the non-defaulting
party.

                  23.9. BROKERAGE: Each of the parties hereto warrants to the
other that, except as set forth in Article 1 hereof, such party has not
obligated the other party for any finders', brokers' or other agents'
commission, fees or other remuneration in connection with this Lease; and each


                                       25
<PAGE>   29

shall indemnify and hold the other harmless from and against any and all claims
for such fees alleged to have been incurred by the indemnifying party in
connection with this Lease. Landlord and Tenant acknowledge that Colliers Turley
Martin Tucker has designated agents Hany Abounader and Tom Murray as the Listing
Agents for One Financial Plaza which is delineated under a listing contract with
Landlord. The Listing Agents are acting solely on behalf of Landlord in
connection with this Lease. Landlord and Tenant further acknowledge that
Colliers Turley Martin Tucker has designated agents Clarence Turley, Larry Reed
and Terry McCaffrey as Tenant's agents acting solely on behalf of Tenant.

                  23.10. LEASE ESTOPPEL CERTIFICATE: Tenant from time to time,
upon not less than ten (10) days prior written request by Landlord, will
promptly deliver to Landlord a duly executed Lease Estoppel Certificate in the
Building standard form (attached hereto as Exhibit G).

                  23.11. FORCE MAJEURE: Any prevention, delay or stoppage due to
strikes, lockouts, labor disputes, acts of God, inability to obtain labor or
materials, governmental restrictions, regulations or controls, enemy or hostile
government action, civil commotion, fire or other casualty or other causes
beyond the reasonable control of the party required to perform shall excuse the
performance by such party for a period equal to any such prevention, delay or
stoppage, except for the obligations imposed with regard to Rent and other
charges to be paid by Tenant pursuant to this Lease. In accordance with the
provisions of Section 3.2 of this Lease, in the event any such prevention, delay
or stoppage occurs prior to the date the Premises are ready for occupancy, the
Lease Commencement Date, the Rent Commencement Date and the Lease Expiration
Date shall be delayed for a period equal to any such prevention, delay or
stoppage.

                  23.12. LEASE TERMINATION: This Lease may be terminated only in
accordance with its terms, and no unilateral termination by Tenant or voluntary
surrender of this Lease by Tenant shall be effective unless such termination or
surrender shall be accepted by Landlord in writing.

                  23.13. RELATIONSHIPS: Nothing contained in this Lease shall be
deemed to constitute or be construed to create any relationship between Landlord
and Tenant other than that of lessor and lessee.

                  23.14. AUTHORITY: Each party, in the event that it is a
Corporation, hereby covenants and warrants that (a) it is duly authorized to do
business in the State of Missouri; (b) the person executing this lease on behalf
of the party is an officer of such party duly authorized by such party to sign
and execute this Lease on such party's behalf; and (c) this Lease is a valid and
binding obligation of such party, enforceable in accordance with the Lease's
terms.

                  23.15. NON-BINDING UNLESS SIGNED; COUNTERPARTS; FACSIMILE
COPIES: Submission of the form of this Lease for examination shall not bind
Landlord in any manner, and no lease or other obligation of Landlord shall arise
until this instrument is signed by both Landlord and Tenant, and delivery is
made to each party. This Lease may be executed in counterparts, each of which
shall constitute an original. The parties may sign this Lease by telefaxed
copies, and any such telefaxed copy shall be deemed to be an original and no
objection shall be made to the introduction into evidence of any telefaxed copy
on grounds related to the


                                       26
<PAGE>   30

telefaxed copy not being an original, but, in such event, executed originals
shall be forwarded to the other parties at the request of any party.

                  23.16. RIGHTS: No rights to any view or to light or air over
any property, whether belonging to Landlord or any other person are granted to
Tenant by this Lease.

                  23.17. REQUIREMENTS OF LENDER: If a lender requires as a
condition to lender's lending funds, the repayment of which is to be secured by
a financial encumbrance on the Building, that certain modifications be made to
this Lease, which modifications will not require Tenant to pay any additional
amounts or otherwise materially change the rights or obligations of Tenant
hereunder, Tenant shall, upon Landlord's reasonable request, execute appropriate
instruments effecting such modifications.

                  23.18. LEASE PAYMENTS: Landlord shall have the right to apply
payments received from Tenant pursuant to this Lease (regardless of Tenant's
designation of such payments) to satisfy obligations of Tenant hereunder in such
order and amounts as Landlord in Landlord's sole discretion may elect.

                  23.19. PARKING SPACES: Tenant shall have the use of the number
of reserved parking spaces in the Building Garage as set forth in Article 1
hereof and shown on Exhibit J on a 24 hour basis. Landlord shall mark such
spaces as "reserved" but shall have no obligation to monitor the use of such
spaces. Subject to the continued effectiveness of the lease for the St. Louis
Centre Garage, Tenant shall have the use of the number of unreserved parking
spaces in the St. Louis Centre Garage as set forth in Article 1 hereof during
Normal Business Hours and upon payment of the Monthly Rent therefor set forth in
Article 1 for such space(s), which Monthly Rent may be changed by Landlord upon
thirty (30) days advance written notice given to Tenant to a rate not exceeding
the lowest published (or otherwise objectively verifiable) monthly rate in the
St. Louis Centre Garage, but in any event not lower than the rate for such
spaces charged by the LCRA to the Landlord pursuant to the lease for the St.
Louis Centre Garage.

                  23.20. LANDLORD'S LIABILITY: Notwithstanding any other
provision hereof to the contrary, Landlord or Landlord's agents shall not be
liable for any damage to property entrusted to employees or agents of Landlord,
nor for loss of or damage to any property by theft or otherwise, nor for any
injury or damage to property resulting from fire, explosion, falling plaster,
steam, gas, electricity, water or rain which may leak from any part of the
Building or from the pipes, appliances or plumbing works therein or from the
roof, street or subsurface or from any other place or resulting from dampness or
any other cause whatsoever. Landlord or Landlord's agents shall not be liable
for interference with the light or other incorporeal hereditaments, nor shall
Landlord be liable for any latent defect in the Premises or in the Building.
Tenant shall give prompt notice to Landlord in case of fire or accidents in the
Premises, in the Storage Area, or in the Building or of defects therein or in
the fixtures or equipment.

                  23.21. CONFIDENTIALITY: The terms and conditions of this Lease
are confidential and may not be disclosed by Tenant or Tenant's Representatives
to any third parties without the prior written consent of Landlord.


                                       27
<PAGE>   31

                  23.22. TENANT'S FINANCIAL STATEMENTS: Tenant represents and
warrants to Landlord that the financial statements delivered to Landlord prior
to the execution of this Lease, if Landlord requested such financial statements,
properly reflect the true and correct value of all the assets and liabilities of
Tenant and Guarantors, if any. Tenant acknowledges that in entering into this
Lease, Landlord is relying upon such statements. Tenant shall, upon ten (10)
days prior written notice from Landlord, provide Landlord with a current
financial statement and financial statements two (2) years prior to the current
financial statement year, but Landlord shall not be entitled to make such a
request more than one (1) time per calendar year. Such statement shall be
prepared in accordance with generally accepted accounting principles and, if
such is the normal practice of Tenant, shall be audited by an independent
certified public accountant.

                  23.23. LANDLORD'S DEFAULT: In the event of any default on the
part of Landlord, Tenant shall give notice by certified mail to any holder of a
financial encumbrance covering the Building, whose address shall have been
furnished to the Tenant, and shall offer such holder a reasonable opportunity to
cure the default, which time period shall not be any shorter than the period set
forth in Section 17.2 of this Lease.

                  23.24. SIGNAGE: Tenant shall have the right to install signage
in the locations depicted on Exhibit A-1 to this Lease (the "Signage Plan"),
which signage shall be subject to compliance with all applicable laws, statutes,
rules, regulations and ordinances. Tenant further acknowledges that (i) any
exterior signage on the side of the Building facing Broadway shall be at an
elevation below the elevation at which Stifel, Nicolaus & Company, Incorporated
("Stifel") has exclusive signage rights pursuant to its lease with Landlord
dated as of September 30, 1998 for space in the Building (the "Stifel Lease"),
and (ii) any exterior signage on the side of the Building facing Washington
shall be at an elevation below the elevation at which Stifel is permitted to
maintain signage pursuant to the Stifel Lease. In the event the locations or
other features of the signage described on Exhibit A-1 to this Lease shall not
be permissible under applicable laws, statutes, rules, regulations or ordinances
or under the Stifel Lease, Landlord and Tenant agree to use reasonable efforts
to adjust the standards for such signage in such manner as may be necessary to
provide substantially equivalent identification of Tenant's business (which
adjustment, if any, shall be reflected in an acknowledgment agreement prepared
by Landlord and delivered to Tenant, and countersigned by Tenant). Landlord
agrees, as an accommodation to Tenant, to cooperate with Tenant to obtain
Stifel's consent for Tenant's signs; provided, however, that Landlord shall not
be obligated to incur any costs, waive any legal rights or make any concessions
in connection with said cooperation.

                  All such signs shall be subject to Landlord's prior written
approval, which approval shall not be unreasonably withheld, conditioned or
delayed.

                  23.25. WAIVER OF TRIAL BY JURY: Tenant hereby agrees not to
elect a trial by jury of any issue triable of right by jury, and waives any
right to trial by jury fully to the extent that any such right shall now or
hereafter exist with regard to the claim, counterclaim or other action arising
in connection therewith. This waiver of right to trial by jury is given
knowingly and voluntarily by Tenant, and is intended to encompass individually
each instance and each issue to which the right to a trial by jury would
otherwise accrue. Landlord is hereby authorized to file a copy of this paragraph
in any proceeding as conclusive evidence of this waiver by Tenant.


                                       28
<PAGE>   32

                  23.26. HEADINGS: The Article and/or Section headings and the
Table of Contents in this Agreement are included herein for convenience of
reference only and shall not constitute a part of this Agreement for any other
purpose.

                  23.27. TIME OF THE ESSENCE: Time is of the essence with
respect to the performance and observance of all of the terms, covenants and
conditions hereof by Tenant.

                  23.28. LANDLORD'S FEES. Whenever Tenant requests Landlord to
take any action or give any consent required or permitted under this Lease,
Tenant shall reimburse Landlord for Landlord's reasonable out-of-pocket expenses
incurred in reviewing the proposed action or consent, including, without
limitation, reasonable attorneys', engineers' or architects' fees, within ten
days after Landlord's delivery to Tenant of a statement of such costs. Tenant
shall be obligated to make such reimbursement without regard to whether Landlord
consents to any such proposed action.

                  23.29. TELECOMMUNICATIONS. Tenant and its telecommunications
companies, including, but not limited to, local exchange telecommunications
companies and alternative access vendor services companies, shall have no right
of access to and within the Building for the installation and operation of
telecommunications systems, including, but not limited to, voice, video, data
and any other telecommunications services provided over wire, fiber optic,
microwave, wireless and any other transmission systems, for part or all of
Tenant's telecommunications within the Building and from the Building to any
other location without Landlord's prior written consent.

                  23.30. DISCLAIMER OF IMPLIED WARRANTIES. Landlord expressly
disclaims any implied warranty that the Premises are suitable for Tenant's
intended commercial purpose, and Tenant's obligation to pay rent and additional
rent hereunder is not dependent upon the condition of the Premises or the
performance by Landlord of its obligations hereunder, and, except as otherwise
expressly provided herein, Tenant shall continue to pay the rent and additional
rent, without abatement, or reduction (except as expressly set forth in Section
7.3 and Articles 13 and 14 of this Lease) or setoff or deduction notwithstanding
any breach by Landlord of its duties or obligations hereunder, whether express
or implied.

                  23.31. LEASE YEAR. The term "lease year" means a period of
time during the term of this Lease conforming to the following: The first lease
year means the period commencing on the Lease Commencement Date and ending
August 31, 2002 (subject to adjustment in accordance with the provisions of this
Lease) and succeeding lease years during the term of this Lease shall commence
and end on dates corresponding to those on which the first lease year commences
and ends.

                  REMAINDER OF PAGE INTENTIONALLY LEFT BLANK


                                       29
<PAGE>   33

                  IN WITNESS WHEREOF, the undersigned have caused this Lease to
be signed and delivered on their behalf on the dates set forth below.

TENANT:

JACOBS ENGINEERING GROUP, INC.

By:______________________________
   Name: ________________________
   Title:________________________

Date:____________________________



LANDLORD:

EBS BUILDING, L.L.C.

By:      PricewaterhouseCoopers LLP, its Manager,


By: _______________________________
    Name:__________________________
    Title:_________________________

Date:______________________________


                                       30
<PAGE>   34

                                    EXHIBIT A
                                   FLOOR PLAN



                                       A-1
<PAGE>   35

                                   EXHIBIT A-1
                                  SIGNAGE PLAN



                        [ATTACH DRAWING OF SIGN LOCATION]


                                       A-1

<PAGE>   36

                                    EXHIBIT B


                              INTENTIONALLY OMITTED


                                       B-1


<PAGE>   37
                                    EXHIBIT C
                      WORK TO BE PERFORMED ON THE PREMISES

                  The timing of the plan submittal and approval process and the
related timing, delivery and approval requirements (collectively the "Approval
Procedures") is very important to completion of construction in the Premises and
the readiness of the Premises for occupancy on the Lease Commencement Date. Each
party agrees to comply with the Approval Procedures and the timing, as stated in
Paragraph B and C below, in order to prevent a delay in the Lease Commencement
Date. In the event that any delay by Tenant in the Approval Procedures or other
Tenant Delays should delay the readiness of the Premises for occupancy on the
Lease Commencement Date, the Lease shall nevertheless continue in effect, and
Rent shall be due and payable on the Rent Commencement Date, without abatement.

                  A. TENANT IMPROVEMENT ALLOWANCE. Up to Three Million Two
Hundred Eighty Seven Thousand Eight Hundred Thirty Five and 00/100 Dollars
($3,287,835.00) (consisting of Twenty and 00/100 Dollars ($20.00) per rentable
square foot for the 151,893 rentable square feet located on the Second, Third,
Fourth and Eleventh Floors of the Premises and Twenty Five and 00/100 Dollars
per rentable square foot for the 9,999 rentable square feet located on the First
Floor of the Premises) (the "Tenant Improvement Allowance"), to be used only for
(i) the Construction Costs (as hereinafter defined), including without
limitation, reasonable space planning, preparation of construction drawings,
materials, interior signage, the cost of any construction permits, and
Landlord's construction management fee in the amount of five percent (5%) of the
aggregate Construction Costs, and (ii) Tenant's Moving Expenses, as defined
below, up to Eight Hundred Nine Thousand Four Hundred Sixty and 00/100 Dollars
($809,460.00) (the "Moving Expense Sub-Allowance"). The term "Moving Expenses"
shall mean moving materials, labor, advertisements, business cards, stationery,
phone listings, hiring temporary employees relating to the move, and the like.
The Tenant Improvement Allowance shall not include the costs and expenses
incurred by Landlord to perform certain work to the Second, Third, Fourth and
Eleventh Floors of the Premises necessary to deliver the same in "white-box"
condition prior to the commencement of construction of the tenant improvements,
which "white-box" work to be performed by Landlord is detailed in Schedule 1
attached hereto and incorporated herein by reference. Landlord shall have no
"white box" obligations with respect to the First Floor of the Premises.
Delivery of the Second, Third, Fourth and Eleventh Floors of the Premises in
"white-box" condition shall not require Landlord to replace any light fixtures
or to replace the ceiling grid, unless otherwise expressly provided in Schedule
1 hereto. The Tenant Improvement Allowance shall also not include the costs and
expenses incurred by Landlord to install security glass around the open atrium
and the stairwells on Floors Three and Four of the Premises and to construct a
corridor on the First Floor of the Premises. The Tenant Improvement Allowance
shall not, however, be used for the purchase of Tenant's furnishings (other than
permanently affixed improvements, such as wallpaper and casework), trade
fixtures, equipment or supplies, all of which shall be paid for by Tenant,
without allowance or reimbursement from Landlord.

                  B. CONTRACTOR FOR THE TENANT IMPROVEMENTS. At Tenant's
request, Landlord has agreed that Interior Systems Contracting, Inc., a Missouri
corporation, d/b/a ISC ("ISC") shall be engaged by Landlord as the contractor
for the construction of the improvements


                                      C-1
<PAGE>   38
to the Premises. Landlord's agreement is conditioned upon ISC agreeing to
indemnify Landlord for any and all loss arising out of or relating to ISC's
failure to complete the improvements to the Premises on or prior to October 1,
2001, to the extent such failure is not caused by a Tenant Delay (as defined in
Section 3.2 of the Lease) or force majeure.

                  In the event ISC does not agree to the foregoing indemnity,
Landlord shall obtain additional construction bids from ICS and Niehaus
Construction Co. Tenant and Landlord shall each be provided with a copy of each
bid and an opportunity to review the same. The contractor for the improvements
to the Premises must be jointly approved by Tenant and Landlord, and shall be
engaged by Landlord. Tenant shall approve the contractor promptly upon request
by Landlord, and in any event within four (4) business days after receipt of the
last of the foregoing bids.

                  Concurrent with the delivery of its construction bid, the
contractor for the improvements to the Premises shall deliver to Landlord and
Tenant a proposed construction schedule, committing to a date upon which the
Premises shall be ready for occupancy. In the event that such date is after
October 1, 2001, Landlord and Tenant shall each execute and deliver to the other
an amendment to this Lease stipulating as to any adjustments to the Lease
Commencement Date as may be necessary to permit said contractor to deliver the
Premises ready for occupancy. Under such circumstance, the Rent Commencement
Date shall remain September 1, 2002, subject to adjustment pursuant to Section
3.2 of the Lease.

                  C. APPROVAL PROCEDURES. The following paragraphs set forth the
process for approval of the space plan and construction documents:

                                    1. On or before March 19, 2001, Landlord and
                  Tenant shall inspect the Premises with Landlord's demolition
                  contractor to determine the demolition schedule (the
                  "Demolition Schedule"), which inspection shall include the
                  identification by Tenant of any and all existing improvements
                  that Tenant determines, in its reasonable discretion, to
                  retain for use in the Premises (the "Salvaged Improvements");
                  provided, however, that in the event the retention of the
                  Salvaged Improvements causes an increase in Landlord's
                  demolition costs relating to Landlord's "white-box" work,
                  Landlord shall provide Tenant written notification of such
                  increase on or before March 22, 2001, and Tenant shall
                  thereafter have three (3) business days to notify Landlord in
                  writing either (i) confirming the retention of said Salvaged
                  Improvements (in which case any such increase shall be
                  deducted from the Tenant Improvement Allowance) or (ii)
                  rescinding its request for the retention of the Salvaged
                  Improvements (in which case Landlord shall cause the
                  demolition of the same, at Landlord's cost). In the event
                  Tenant fails to respond within said three (3) business day
                  period, the Salvaged Improvements shall be deemed to have been
                  retained by Tenant and Landlord shall deduct said increased
                  demolition costs from the Tenant Improvement Allowance.

                                    2. Tenant shall, at Tenant's sole cost and
                  expense, prepare a preliminary space plan for the proposed
                  improvements to the Premises, which


                                      C-2
<PAGE>   39
                  Tenant shall deliver to Landlord for review and approval not
                  later than April 16, 2001. Landlord shall then have five (5)
                  business days to return the same to Tenant, marked approved,
                  or with Landlord's necessary changes indicated and Tenant
                  shall thereafter incorporate said changes and return the same
                  to Landlord within five (5) business days (the preliminary
                  space plan, as revised by Tenant to incorporate Landlord's
                  necessary changes is hereinafter referred to as the
                  "Preliminary Space Plan"). Tenant may prepare further
                  modifications to the Preliminary Space Plan from time to time
                  prior to Tenant's CD Submittal Date and Tenant shall submit
                  revised plans to Landlord with regard to any material
                  modifications to the Preliminary Space Plan. Landlord shall
                  have five (5) business days after receipt of Tenant's
                  modifications to the Preliminary Space Plan to approve or
                  indicate modifications and return the same to Tenant.

                                    3. Tenant shall commence the preparation of
                  the plans and specifications (the "Construction Documents")
                  necessary to construct the Premises, and Tenant shall deliver
                  the Construction Documents to Landlord for review and approval
                  no later than June 4, 2001 (the "Tenant's CD Submittal Date").
                  Landlord shall review the Construction Documents and shall
                  either return the same to Tenant, marked approved or with
                  Landlord's necessary changes indicated no later than June 11,
                  2001 (the "Landlord's CD Approval Date"). In the event that
                  Landlord indicates changes to the Construction Documents,
                  Tenant shall promptly make the indicated changes and return
                  the revised Construction Documents to Landlord for final
                  approval on or prior to June 18, 2001 ("Tenant's Subsequent CD
                  Submittal Date"). Construction Documents, with the requested
                  revisions from Landlord, must be signed by the Tenant on or
                  before June 22, 2001 (the "Approved Construction Documents")
                  to authorize Landlord to complete the work to the Premises
                  (work on the Premises will not begin until such approval is
                  received by Landlord).

                                    4. Within ten (10) business days of receipt
                  of the Approved Construction Documents, Landlord will provide
                  to Tenant the cost of the construction of such work and any
                  costs attributable to the retention of the Salvaged
                  Improvements (collectively, the "Construction Costs"). If the
                  Construction Costs are not in excess of the Tenant Improvement
                  Allowance, Landlord shall proceed promptly with the necessary
                  construction. If the Construction Costs are in excess of the
                  Tenant Improvement Allowance, Landlord will so advise Tenant,
                  detailing the costs and overruns and will permit Tenant a
                  reasonable time (not to exceed five (5) days from the date of
                  such notice) to revise the Construction Documents (in a manner
                  acceptable to Landlord) to reduce the Construction Costs or
                  approve the Construction Costs with such excess costs payable
                  by Tenant as set forth below.

                  D. CONSTRUCTION. In accordance with the Approved Construction
Documents, Landlord shall cause the construction of the improvements to the
Premises by ISC or such other contractor as approved by Landlord and Tenant
pursuant to Section B above. In the event the Construction Costs pursuant to the
Approved Construction Documents exceed the


                                      C-3
<PAGE>   40
Tenant Improvement Allowance, Tenant shall be responsible for payment of the
excess costs. Tenant shall pay such excess costs to Landlord as follows:

                           1. At any time and from time to time after Landlord's
                  expenditure of the Tenant Improvement Allowance (net of
                  customary holdbacks), Landlord shall provide Tenant with a
                  written request for payment of all or a portion of Tenant's
                  share of the Construction Costs accrued through the date of
                  such request (the "Payment Request"), which Payment Request
                  shall identify the sum due Landlord and shall include a copy
                  of ISC's invoice (if any). Landlord shall not make a Payment
                  Request more frequently than twice per month.

                           2. Tenant shall have five (5) business days from
                  receipt of the Payment Request to issue a check to Landlord in
                  the amount requested. Tenant's failure to pay each such
                  Payment Request within the time period herein provided shall
                  constitute a Tenant Delay pursuant to Section 3.2 of the
                  Lease.

                  No credit shall be given if the cost of construction, pursuant
to the Approved Construction Documents, is less than the Tenant Improvement
Allowance.

                  In the event that Tenant requests any modifications to the
Approved Construction Documents ("Change Orders"), Tenant, upon written approval
from the Landlord of the Change Order, will pay Landlord the total amount of
such costs as estimated by or on behalf of Landlord within ten (10) days of
Landlord's approval of the Change Order.


                                      C-4
<PAGE>   41
                             SCHEDULE 1 TO EXHIBIT C

                           Landlord's "White-Box" Work

         Landlord shall, at Landlord's sole cost and expense, perform the
following "white-box" work in the Second, Third, Fourth and Eleventh Floors of
the Premises:

         1.       Demolition of all non-load bearing walls

         2.       Removal of all unused telephone and data cable

         3.       Drywall and tape all remaining walls

         4.       Cap or place outlets on all remaining electric locations

         5.       Maintain light fixtures at all current locations

         6.       Remove and clean all discolored ceiling tiles or, at
                  Landlord's sole option, replace all ceiling tiles with
                  comparable "new" ceiling tiles, to be stacked on each floor
                  (installed, at Landlord's cost, upon completion of
                  construction of the improvements to the Premises)

         7.       All ceiling grids to be consistent across the respective
                  floors (but not from floor to floor)

         8.       Floors to be in broom-clean condition, free of all flooring
                  materials and electrical outlets

         9.       Retention of Salvaged Improvements

         10.      All existing mechanical, electrical and plumbing to be placed
                  in working condition.

         11.      Removal of the halon system from the Second Floor of the
                  Premises.


                             SCHEDULE 1 TO EXHIBIT C
                                        1
<PAGE>   42
                                    EXHIBIT D
                                 BUILDING RULES

                  Tenant's use of the Building and Premises shall be governed by
the following rules, which Landlord shall use reasonable efforts to enforce on a
uniform basis. Landlord reserves the right to unilaterally amend or add to the
rules, and such amendments and additions shall be effective when notice of the
same is given to Tenant in the manner provided in the Lease.

                  1. Nothing shall be displayed, painted or affixed by Tenant on
any part of the exterior or interior of the Building (except within the
Premises) without the prior written consent of Landlord, and then only of such
color, size, style and material as shall be approved by Landlord. Nothing shall
be placed in the Premises which may be visible from the exterior of the Building
(including window treatments) without the prior written consent of Landlord.

                  2. Landlord shall furnish Tenant with two (2) keys to each
door lock for the Premises. Additional keys shall be procured from Landlord and
paid for by Tenant. No additional or replacement locks shall be placed on any
door of the Premises, and Tenant shall not permit duplicate keys to be made.
Tenant shall be solely responsible for the security of all keys to the Premises.
All keys furnished to Tenant shall be surrendered to Landlord at the termination
of the Term.

                  3. If Tenant desires additional wiring connections, Landlord
shall direct the electricians as to where the wires are to be introduced and
without such directions no boring or cutting for wiring shall be permitted.

                  4. Tenant shall not install or operate any steam or internal
combustion engine, boiler, machinery, refrigerating or heat generating device or
air conditioning apparatus in or about the Premises or carry on any mechanical
business therein. Tenant shall not install any vending machines other than for
use by Tenant's employees; however Tenant may install a refrigerator, microwave
or coffee maker in the Premises for use solely by Tenant's employees.

                  5. The common areas of the Building shall not be obstructed by
Tenant or used in any way except for ingress and egress to and from the offices.
Tenant shall place no objects outside Tenant's premises.

                  6. The bathroom fixtures shall not be used for purposes other
than those for which they were constructed. The cost of repairing any damage
caused by Tenant resulting from misuse of such fixtures shall be borne by
Tenant.

                  7. Tenant shall not permit littering of the common areas of
the Building.

                  8. Tenant shall not make noises, cause disturbances or
vibrations or use any electrical or electronic devices or other devices that
emit sound or other waves or disturbances or create odors, any of which may be
offensive to other tenants of the Building or which would interfere with the
operation of any device or equipment or radio or television broadcasting or
reception from or within the Building or elsewhere, and shall not place or
install any musical


                                      D-1
<PAGE>   43
instrument or equipment or any similar device inside or outside the Premises
without the prior written consent of Landlord. The use thereof, if permitted,
shall be subject to control of Landlord to the end that others shall not be
disturbed or annoyed.

                  9. Tenant shall not waste utility services and shall cooperate
fully with Landlord to assure the most effective operation of the Building's
HVAC system and shall not adjust any controls other than thermostats installed
for Tenant's use. Tenant shall keep corridor door(s) closed.

                  10. Tenant assumes full responsibility for protecting Tenant's
space from theft, robbery and pilferage, which includes keeping doors locked and
other means of entry to the Premises closed and secured.

                  11. No animals, birds, bicycles or other vehicles shall be
allowed in any part of the Building without the prior consent of Landlord.

                  12. Any person or person (other than the janitor of Landlord)
who shall be employed for the purpose of cleaning or maintaining the Premises
shall be employed at Tenant's cost, subject to the terms of the Lease, and
Landlord shall in no way be responsible for any loss of property on or from the
Premises, however occurring, by such person.

                  13. Tenant shall not accumulate or store on the Premises any
waste paper, discarded records, books and paper files, sweepings, rags, rubbish
or other combustible matter. Tenant shall not place in any trash receptacle any
material which cannot be disposed of in the ordinary course, and Tenant shall
keep all trash within Tenant's Premises. All garbage and refuse disposal shall
be made in accordance with Landlord's instructions as designated from time to
time.

                  14. Tenant shall not make any room to room canvass to solicit
business from other tenants in the Building and shall not exhibit, sell, or
offer to sell, use, rent or exchange any item or service in or from the Premises
unless within the Permitted Use.

                  15. Landlord reserves the right to exclude from the Building
all disorderly persons, persons under the influence of alcohol or a controlled
substance, idlers and peddlers, solicitors, and persons entering in crowds or in
such unusual numbers as to cause inconvenience to the tenants of the Building.

                  16. Any parking spaces included in the Lease shall be used
only for the personal automobiles, sports utility vehicles, vans and pick-up
trucks (all of widths, heights, lengths and other dimensions fitting within the
garages and Building Standard Parking spaces) of Tenant and Tenant's employees
and guests (no trucks, motor homes and the like). Landlord reserves the right to
designate locations for one or more of such parking spaces. Upon Landlord's
request, Tenant promptly shall furnish Landlord the names, vehicle descriptions
and vehicle license numbers of each authorized user of Tenant's parking spaces.
Tenant shall be liable for all costs and expenses suffered or incurred by
Landlord in the towing of illegally parked


                                      D-2
<PAGE>   44
vehicles of Tenant, Tenant's employees or guests. Landlord shall have no
obligation to monitor the use of any such spaces.

                  17. Tenant shall comply with all Conditions (as defined in the
Lease) in connection with Tenant's use and occupancy of the Premises.

                  18. All deliveries to the Premises shall be subject to the
reasonable control of Landlord as to place and time of deliveries.

                  19. The common areas of the Building are a no smoking area in
which no smoking of any kind, including but not limited to cigarettes, cigars,
pipes, or any other device, is permitted except in an area specifically
designated by Landlord as an area where smoking is permitted. Landlord shall not
be responsible for violations of this provision by any Tenant of the Building,
Tenant's employees, visitors, contractors, or subcontractors. In the event
Landlord seeks to enforce this provision against Tenant, Tenant shall pay all
costs and expenses of every kind including, without limitation, all court costs
and attorneys fees and charges. In the event Landlord seeks any injunctive
relief to prevent violations of this provision of the Lease, Tenant agrees that
if a bond is required by the court, that the amount of such bond not exceed
$100.00. Landlord further reserves the absolute right to designate the entire
areas of the Builders, grounds and Premises as non-smoking.

                  20. Tenant may not advertise the sale or issuance of
securities from the first floor common areas of the Building or from first floor
leased premises visible from the first floor common areas or exterior of the
Building (provided that for purposes of this prohibition the term "securities"
shall not be considered to include certificates of deposit and similar bank
accounts customarily sold or issued in connection with retail and commercial
banking operations). If the Premises are situated on the first floor of the
Building, Tenant may not use the Premises for the sale or issuance of securities
(subject to the same proviso set forth in the preceding sentence).


                                      D-3
<PAGE>   45
                                    EXHIBIT E
                          LEASE COMMENCEMENT AGREEMENT

TENANT:           JACOBS ENGINEERING GROUP, INC.

LANDLORD:         EBS BUILDING, L.L.C.

BUILDING:         ONE FINANCIAL PLAZA

PREMISES:
                  -----------------------------------------
DATE OF ORIGINAL LEASE EXECUTION:
                                    -----------------------
                  This Lease Commencement Agreement is executed by Tenant and
Landlord pursuant to the provisions of the Lease referenced above, and shall be
attached thereto and become a part thereof for all purposes.

                  1. Tenant hereby acknowledges that it has inspected the
Premises and finds same to be substantially complete, in a tenantable condition
and now suitable for Tenant's intended use.

                  2. Tenant and Landlord hereby agree that all work to be done
to the Premises is acceptable and that the only work remaining to be done to the
Premises, all of which is of a minor nature, is as follows:
______________________________________________________. Such work is the
responsibility of _________________________ Landlord to complete and said party
hereby agrees to promptly undertake the completion of same. Tenant hereby agrees
that such work may be completed after it has taken occupancy of the Premises and
the term of the Lease has commenced; and further, that Tenant shall not be
entitled to any abatement of Tenant's rent or other compensation as a result
thereof.

                  3. Tenant and Landlord hereby agree, pursuant to Section 3.2
of the Lease, that the actual Lease Commencement Date of the term of the Lease
shall be __________________ and that the rent, as provided for in the Lease,
shall commence as of ___________, 2002, and further, that the Lease will
terminate at Midnight (local time) on ______________________, if not otherwise
terminated pursuant to the previsions of the Lease.

                  Executed this ______________ day of ________________, 20____

                                      E-1
<PAGE>   46
TENANT:

JACOBS ENGINEERING GROUP, INC.

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

Date:
     ------------------------------



LANDLORD:

EBS BUILDING, L.L.C.

By:      PricewaterhouseCoopers LLP, its Manager


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

Date:
     ------------------------------


                                      E-2
<PAGE>   47
                                    EXHIBIT F
                                     FORM 1
                            CONTRACTOR'S LIEN WAIVER

STATE OF MISSOURI )
                  )  SS.  WAIVER
CITY OF ST. LOUIS )

                  WHEREAS, _____________________ ("Contractors") has/have been
employed by JACOBS ENGINEERING GROUP, INC., as Tenant of the Premises described
below, to perform construction as a general contractor upon the following
described premises, to-wit:


("the Premises"), the specific terms and conditions of such employment being
governed by that certain Agreement dated the ________ day of __________, 20__,
and

                  WHEREAS, EBS Building, L.L.C. ("Landlord") is Landlord of the
Premises.

                  NOW, THEREFORE, for and in consideration of the sum of Ten
Dollars ($10.00) and other good and valuable consideration, the receipt of which
is hereby acknowledged, Contractor does hereby waive any right it may have to
file any and all mechanic's liens, claim of lien or right of lien against
Landlord or Landlord's interest in the Premises, provided by the statutes of the
State of Missouri, upon the above described Premises or any portion thereof.
Further, Contractor hereby acknowledges that Landlord has not contracted for or
agreed to pay for the work or materials called for in the contract described
above. Contractor agrees to look solely to Tenant or Tenant's interest in the
Premises to satisfy any mechanic's lien, right, claim or causes of action which
Contractor may have against Tenant arising out of the above referenced contract.
Contractor shall obtain a similar waiver and acknowledgment from all
subcontractors and suppliers.

                  EXECUTED this ___________day of ______________, 20___.

                                                  CONTRACTOR:

                                                 ----------------------------

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

Subscribed and sworn to before me this         day of               , 20  .
                                       -------        --------------    --

My commission expires:
                      -----------------------------------------------------

                                                              Notary Public

                                        ---------------------

                                       F-1
<PAGE>   48
                                    EXHIBIT F
                                     FORM 2
                             PARTIAL WAIVER OF LIEN

                      (SUBCONTRACTOR OR MATERIAL SUPPLIER)

STATE OF MISSOURI )
                  )       SS.
CITY OF ST. LOUIS )

                  WHEREAS, ____________________ ("Contractors") has/have been
employed by JACOBS ENGINEERING GROUP, INC. , as Tenant of the Premises described
below, to perform construction as a general contractor upon the following
described premises, to-wit:


("the Premises"), the specific terms and conditions of such employment being
governed by that certain Agreement dated the _______ day of _______________,
20_, and

                  WHEREAS, under authority of the above mentioned Agreement,
_______________ has/have employed _______________________ as a subcontractor
material supplier, to perform labor, to furnish materials or to do both upon the
Premises or some portion thereof, the specific terms and conditions of such
employment being governed by that certain Agreement dated the ________ day of
________________, 20_, and

                  WHEREAS, EBS Building, L.L.C. ("Landlord") is Landlord of the
Premises.

                  NOW, THEREFORE, for and in consideration of the sum of Ten
Dollars ($10.00) and other good and valuable consideration, the receipt of which
is hereby acknowledged, subcontractor or material supplier does hereby waive any
right it may have to file any and all mechanic's liens, claim of lien or rights
of lien against Landlord or Landlord's interest in the Premises, provided by the
statutes of the State of Missouri, upon the above described Premises or any
portion thereof. Further, subcontractor or material supplier hereby acknowledges
that Landlord has not contracted for or agreed to pay for the work or materials
called for in the contract described above. Subcontractor or material supplier
agrees to look solely to Tenant to satisfy any mechanic's lien, right, claim or
cause of action which subcontractor or material supplier may have against Tenant
arising out of the above referenced contract.

                  EXECUTED this ______ day of ____________, 20__.

                                                SUBCONTRACTOR OR
                                                MATERIAL SUPPLIER:

                                                ------------------------------

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

                                      F-2
<PAGE>   49
                                    EXHIBIT G
                           LEASE ESTOPPEL CERTIFICATE


LEASE DATE:

LANDLORD:             EBS Building, L.L.C.

TENANT:               JACOBS ENGINEERING GROUP, INC.

PREMISES:             Suite _____, One Financial Plaza

AREA:                 161,892 Square Feet

MORTGAGEE/
PROSPECTIVE
PURCHASER:

                  The undersigned Tenant in the above Lease hereby certifies to
Mortgagee and to Landlord as follows:

                  1. That the term of the Lease commenced on _________________,
20__, and that Tenant is in full and complete possession of the Premises demised
under the Lease and has commenced full occupancy and use of the Premises, such
possession having been delivered by Landlord and having been accepted by Tenant.

                  2. That the Lease calls for Monthly Base Rent Installments of
$__________ to date, and in addition, Tenant is paying an adjustment to Annual
Base Rent in the amount of $__________ per month which commenced to accrue on
_____________________, 20__.

                  3. That no advance rental or other payment has been made in
connection with the Lease except rental for the current month, and the Rent has
been paid to and including ____________________, 20__.

                  4. That all of the obligations and conditions under the Lease
to be performed to date by Landlord or Tenant have been satisfied, free of
defenses and setoffs, including all construction work in the Premises; except as
follows:

                                       G-1
<PAGE>   50
                  5. That the Lease is a valid lease and in full force and
effect and represents the entire agreement between the parties, that there is no
existing default on the part of Landlord or Tenant in any of the terms or
conditions thereof, and no event has occurred which, with the passing of time or
the giving of notice or both, would constitute an event of default, and that
said Lease: (check one as appropriate)

         (_____) Has not been amended, modified, supplemented, extended, renewed
or assigned.

         (_____) Has been amended, modified, supplemented, extended, renewed or
assigned as follows by the following described agreements:

                  6. That the Lease provides for a term of __________ months and
the term of the Lease expires on __________________, 20__.

                  7. There is no action, voluntary or involuntary, pending
against Tenant under the bankruptcy laws of the United States or any state
thereof.

                  8. That this Certificate is being made knowing that the
Mortgagee and Landlord are relying upon the representations made herein.

                  9. This Certificate may be relied upon by the prospective
purchaser's mortgage as if addressed thereto.

                  IN WITNESS WHEREOF, the undersigned Tenant has executed this
Lease Estoppel Certificate as of the _____ day of ___________________, 20__.

TENANT:

JACOBS ENGINEERING GROUP, INC.

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

Date:
     ------------------------------

                                      G-2
<PAGE>   51
                                    EXHIBIT H
             ONE FINANCIAL PLAZA MEETING ROOMS RULES AND REGULATIONS


1.       Meeting Rooms to be scheduled with the Property Manager on a first
         come, first serve basis.

2.       Equipment in the Meeting Rooms is the property of the Landlord. Tenant
         shall operate the equipment while occupying a Meeting Room.

3.       Meeting Room equipment shall not be removed without prior written
         consent of the Property Manager.

4.       Tenant shall be responsible for setting up and returning the Meeting
         Rooms to the original configuration.

5.       Landlord shall maintain the Meeting Rooms and the equipment therein.

                                      H-1
<PAGE>   52
                                    EXHIBIT I
             SUBORDINATION, ATTORNMENT AND NON-DISTURBANCE AGREEMENT

                  THIS SUBORDINATION, ATTORNMENT AND NON-DISTURBANCE AGREEMENT
made and entered into as of this _____ day of ___________, ______, by and
between ______________________________________________________________________,
a ______________ corporation (hereinafter called "Lender"), and JACOBS
ENGINEERING GROUP, INC., a _______ corporation (hereinafter called "Tenant"),

                  WITNESSETH:

                  WHEREAS, Lender is the owner and holder of a certain
promissory Note dated ________________, 19__, in the face principal amount of
________________________ Dollars ($_________________), which is secured by a
Deed of Trust and Security Agreement of even date therewith recorded in Book
_______, Page __, St. Louis City Records (the "Deed of Trust") encumbering
______________________________________________________ as described therein,

                  WHEREAS, Tenant has entered into a certain Lease dated
_____________, 2001 with EBS Building, L.L.C., a Delaware limited liability
company, demising certain premises therein described at 501 North Broadway, St.
Louis, Missouri 63102 (together with any further extensions, renewals or
modifications thereof, the "Lease"),

                  WHEREAS, Tenant has requested Lender to recognize Tenant's
right to the Premises demised by the Lease in the event of foreclosure of the
Deed of Trust,

                                      I-1
<PAGE>   53
                  NOW THEREFORE, for and in consideration of the premises and
the mutual covenants hereof, the parties hereto stipulate, covenant, and agree
as follows:

                  1. Lender agrees that so long as Tenant shall not be in
default under the Lease beyond any applicable cure period, (a) Tenant's right of
possession and enjoyment of the Premises demised by the Lease shall be and
remain undisturbed and unaffected by any foreclosure or other proceedings
involving the Deed of Trust and (b) Lender and any purchaser at a foreclosure
sale involving the deed of trust shall recognize Tenant as Tenant under the
Lease.

                  2. Tenant agrees to recognize Lender or any purchaser at a
foreclosure sale involving the Deed of Trust as its Landlord under the Lease for
that part of the Premises demised by the Lease without the necessity of any
other or further attornment than in this paragraph contained (and this paragraph
shall be considered an attornment). Tenant hereby waives any and all rights to
terminate the Lease by reason of any foreclosure of the Deed of Trust, and if
any court holds the Lease terminated by reason of a foreclosure of the Deed of
Trust, this Agreement shall be deemed a new lease for the balance of the term of
the Lease at the same rental therein provided, and upon the same terms and
conditions as therein provided.

                  3. Neither Lender nor any purchaser at foreclosure shall, at
any time after, be:

                           (a) liable for any act or omission of a prior
                  landlord, except that Lender, upon succeeding to Landlord's
                  interest and while in privity of estate with Tenant, and only
                  during such period, will remain obligated to cure any on-going
                  defaults;

                           (b) subject to any offsets or defenses which Tenant
                  might have against any prior landlord arising after the time
                  Lender ceased to be a partner in the entity which is Landlord
                  under the Lease and is not Landlord under the Lease except
                  such offsets and defenses as are expressly provided for in the
                  Lease and arise out of

                                      I-2
<PAGE>   54
                  Landlord defaults of which Tenant notified Lender at the time
                  of the alleged default;

                           (c) bound by any prepayment of rent or additional
                  rent which Tenant might have paid to any prior landlord more
                  than thirty (30) days prior to the due date of such
                  installment; or

                           (d) bound by any agreement or modification of the
                  Lease without the consent of Lender (which consent shall not
                  be unreasonably withheld).

                  4. Subject to the provisions hereof, Tenant agrees that the
Lease as it may hereafter be amended, renewed, modified, replaced, substituted
or extended, from time to time, shall in all respects be, and is hereby
expressly made, subject, subordinate and inferior at all times to the lien,
right, title and terms of the Deed of Trust and to all of the terms, conditions
and provisions thereof, and to all advances and/or payments made or to be made
thereunder, as it may have been or may hereafter be amended, increased, renewed,
modified, consolidated, replaced, combined, substituted, severed, split, spread,
refinanced, recast or extended, whether or not such Deed of Trust also covers
other lands and/or buildings and/or leases. Furthermore, nothing contained in
this Agreement shall in any way impair or affect the lien(s) created by the Deed
of Trust.

                  5. This Subordination, Attornment and Non-Disturbance
Agreement shall be binding upon and inure to the benefit of the parties hereto,
their successors and assigns.

                                      I-3
<PAGE>   55
                  6. This Subordination, Attornment and Non-Disturbance
Agreement may be executed by the parties hereto in several counterparts, each of
which shall be deemed to be an original and all of which shall constitute
together but one and the same agreement.

                  IN WITNESS WHEREOF, the undersigned have executed and
delivered this instrument as of the day and year first above written.

                                             [LENDER]


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


                                             JACOBS ENGINEERING GROUP, INC.


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

                                      I-4
<PAGE>   56
STATE OF                                )
         -----------------              )
                                        )   SS:
            OF                          )
-----------    --------------


                  On this day of _______ , ______, before me appeared _________,
to me personally known, who, being by me duly sworn, did say that he is the
__________________of ________________________________________________, a
corporation of the State of ____________, and that the seal affixed to the
foregoing instrument is the corporate seal of said corporation, and that said
instrument was signed and sealed on behalf of said corporation, by authority of
its Board of Directors; and said acknowledged said instrument to be the free act
and deed of said corporation.

                  IN TESTIMONY WHEREOF, I have hereunto set my hand and affixed
my official seal in the and State aforesaid, the day and year first above
written.


                                                    Notary Public

My Commission Expires:

----------------------------


STATE OF                                )
         -----------------
                                        )   SS:
            OF                          )
-----------    --------------

                  On this day of __________ , ______, before me appeared
____________, to me personally known to be the person described in and who
executed the foregoing instrument and who being by me duly sworn, did say that
he is a _____________ of JACOBS ENGINEERING GROUP, INC., a corporation organized
and existing under the laws of the State of _________; and said acknowledged
said instrument to be his free act and deed and the free act and deed of said
corporation.

                  IN TESTIMONY WHEREOF, I have hereunto set my hand and affixed
my official seal in the City and State aforesaid, the day and year first above
written.


                                                        Notary Public

My Commission Expires:

----------------------------

                                      I-5
<PAGE>   57
                                    EXHIBIT J
                                     PARKING

                                      J-1
<PAGE>   58
                                 ADDENDUM NO. 1

                         ATTACHED TO AND MADE A PART OF

                          LEASE DATED FEBRUARY 22, 2001

                   BETWEEN EBS BUILDING, L.L.C., AS LANDLORD,

                       AND JACOBS ENGINEERING GROUP, INC.

                  23.32. TENANT AMENITIES. Tenant shall have the right, upon
prior written notice to Landlord and subject to availability, upon the payment
of an hourly rate of Fifteen and No/100 Dollars ($15.00), not to exceed One
Hundred and No/100 Dollars ($100.00) per day to Landlord, to use the Building's
meeting rooms located on the second floor of the Building and currently named
the "Harvard" and "Founders" rooms, in common with other users designated by
Landlord, as the same may be available from time to time, to be billed by
Landlord on a monthly basis and payable by Tenant within thirty (30) days of
receipt of Landlord's invoice. Landlord reserves the right to increase the
foregoing hourly or per diem rate at any time and from time to time. The use of
such rooms shall be subject to such reasonable rules and regulations as may be
promulgated by Landlord at any time and from time to time (which Landlord shall
use reasonable efforts to enforce in a non-discriminatory manner). Tenant shall
provide written notice to Landlord and Landlord's Building manager not less than
fifteen (15) nor more than forty-five (45) days prior to each day on which it
proposes to use either or both of the "Harvard" and "Founders" rooms pursuant to
the right and license set forth in this Section 23.32.

                  23.33. STORAGE AREA. Landlord hereby leases unto Tenant and
Tenant hereby accepts from Landlord approximately 3,587 rentable square feet of
storage space located on the Second Floor of the Building (Mezzanine Area),
designated as Storage Space S-1A (the "Storage Area"), all as outlined on the
floor plan attached hereto as Exhibit A. The Storage Area shall be made
available to Tenant on or prior to the Lease Commencement Date. The annual rent
for the Storage Area shall be Thirty Five Thousand Eight Hundred Seventy Dollars
($35,870.00) (based on an annual rental rate of Ten and No/100 Dollars ($10.00)
per rentable square foot), payable in equal monthly installments of Two Thousand
Nine Hundred Eighty Nine and 17/100 Dollars ($2,989.17) and shall be added to
Tenant's Annual Base Rent obligations hereunder. The Storage Area shall be
delivered to Tenant in its "as is" condition. Tenant agrees that the Storage
Area may be used only for the storage (and not any use or operation) of
furniture, office equipment, supplies and boxes and may not be used for storage
of any dangerous or noxious materials or the operation of computer equipment.
Tenant's use of the Storage Area shall be in full compliance with the applicable
provisions of the Lease. The term of the lease of the Storage Area shall expire
concurrent with the expiration of the Term of the Lease, unless otherwise
earlier terminated by agreement of the parties.

                  Tenant shall have the on-going right of first refusal to lease
an additional approximately 2,000 rentable square feet of storage space located
on the mezzanine level of the First Floor of the Building (the "Additional
Storage Area"), during the first and second lease years of the initial Term of
this Lease. If Landlord during such period has a bona fide offer from


                                       1
                                 ADDENDUM NO.1
<PAGE>   59
a third party to lease all or a portion of such mezzanine level such that less
than 2,000 rentable square feet of space would thereafter be available to Tenant
for leasing as storage space and Landlord is willing to accept such offer,
Landlord shall so notify Tenant in writing. Landlord's notice shall include a
floor plan depicting the location of the Additional Storage Area to be made
available to Tenant in the event Tenant exercises its rights hereunder. Provided
Tenant is not in default of any monetary obligations hereunder and is not in
default of its non-monetary obligations beyond any applicable cure period as of
the date of Landlord's notice hereunder, Tenant shall have five (5) business
days from the date of Landlord's notice to advise Landlord that Tenant accepts
the Additional Storage Area on the same terms (including rental rate) and
conditions set forth above for the Storage Area, except that the term thereof
shall be coterminous with this Lease. In the event Tenant fails to so notify
Landlord within the time specified or in the event Tenant is in default of its
monetary obligations hereunder or is in default of its non-monetary obligations
beyond any applicable cure period under this Lease as of the date of Landlord's
notice hereunder or at any time during such five (5) business day period
thereafter, Landlord shall be permitted to lease the Additional Storage Area
free from any rights of Tenant hereunder. In the event Tenant exercises its
right of first refusal, the Lease shall be promptly amended in writing to add
the Additional Storage Area to the Storage Area and to stipulate the adjustment
to the annual rent payable in respect of the Storage Area as so expanded. In the
event Tenant exercises its right to lease the Additional Storage Area by its
exercise of its right of first refusal, the Additional Storage Area shall become
part of the Storage Area, subject to the same terms (including rental rate) and
conditions as are contained in this Lease. The Additional Storage Area will be
delivered to Tenant in its "as is" condition and any improvements thereto will
be subject to Landlord's consent and Tenant's obligations with respect to annual
rent for the Additional Storage Area shall begin on the date Landlord delivers
possession of the Additional Storage Area and the term shall end on the last day
of the term of this Lease (as extended or early terminated pursuant to the terms
hereof).

                  23.34. RENEWAL OPTION. Provided that this Lease is in full
force and effect and Tenant is not in default of its monetary obligations
hereunder and is not in default of its non-monetary obligations beyond any
applicable cure period hereunder, Tenant shall have the option to extend the
Term of this Lease on the same terms, conditions and provisions as contained in
this Lease, except as otherwise expressly provided herein, for one (1) period of
five (5) years (the "Extension Period"). If exercised in accordance herewith,
the Extension Period shall commence on the first (1st) day after such scheduled
Lease Expiration Date and the rental rate shall be at the then prevailing market
base rent for comparable quality space in similar buildings in the downtown St.
Louis business district, taking into account all rental terms such as free rent,
moving allowances, allowances for tenant improvements, step rent structure, base
years for operating expense and tax escalation, and lease commissions, if any
(the "Prevailing Market").

                  The renewal option may only be exercised in accordance with
the procedures set forth herein. As a prerequisite to Tenant's right so to
extend the Term of this Lease, not less than nine (9) months prior to the
Expiration Date, Tenant shall, by written notice to Landlord (the "Notice"),
notify Landlord of Tenant's intent to exercise such renewal option and request
that Landlord determine the Prevailing Market rate for the Premises as it would
be during the Extension Period. Within thirty (30) days following Landlord's
receipt of the Notice, Landlord will notify Tenant of such Prevailing Market
rate as reasonably determined by Landlord. Absent

                                        2
                                 ADDENDUM NO.1
<PAGE>   60
any notice of disagreement from Tenant with respect to such determination,
delivered in accordance with the procedures set forth below, Landlord's
determination shall be final and conclusive. In the event Tenant disagrees with
Landlord's determination of the Prevailing Market rate, then Tenant shall notify
Landlord within seven (7) days of Tenant's receipt of Landlord's determination
of such disagreement, including in said notice Tenant's determination of the
Prevailing Market rate. In the event Landlord does not agree with Tenant's
determination, the parties shall have thirty (30) days after Landlord's receipt
of Tenant's notice to reach an agreement as to the Prevailing Market rate. If
Landlord and Tenant fail to reach an agreement as to such Prevailing Market rate
within such thirty (30) day period, the Notice shall be deemed to be revoked and
Tenant's right to exercise such option and all subsequent options shall cease
and be void. Additionally, if the option to extend the Lease Term is not
exercised in the aforesaid manner, the Lease Term and Tenant's rights hereunder
and its rights to occupy and possess the Premises shall expire on the Expiration
Date (i.e., the scheduled Lease Expiration Date).

                  23.35. EXPANSION OPTION. Provided that this Lease is in full
force and effect and Tenant is not in default of its monetary obligations
hereunder and is not in default of its non-monetary obligations hereunder beyond
any applicable cure period, Tenant shall have the right, during the first ninety
(90) days of the Term of this Lease, to lease and occupy all or any portion of
the First Floor, provided that the portion of the First Floor not leased and
occupied by Tenant is configured and located so as to be leaseable to third
parties in accordance with customary market terms reasonably acceptable to
Landlord (the "Expansion Space"). The lease term for the Expansion Space shall
expire coterminous with this Lease. Tenant may exercise this right only by
giving Landlord written notice at any time during the first ninety (90) days of
the Term of the Lease. Annual Base Rent for the Expansion Space shall be charged
at the rate per rentable square foot then in effect for the Premises, which rate
shall increase pursuant to the terms of Section 1.11 of the Lease. In addition,
Tenant's Proportionate Share shall be adjusted to reflect the Expansion Space,
with all other terms of the Lease to remain the same. Landlord shall provide
Tenant with a Tenant Improvement Allowance for the Expansion Space in an amount
equal to $20.00 per rentable square foot (constituting the "Expansion Tenant
Improvement Allowance"). The improvements to be constructed in the Expansion
Space shall be designed and constructed in accordance with the applicable
procedures set forth in Exhibit C and Rent shall commence on a date determined
by Landlord and Tenant, which date shall not be more than ninety (90) days after
Landlord's receipt of written notice of Tenant's exercise of the option for the
Expansion Space. Any costs incurred by Tenant in excess of the foregoing
Expansion Tenant Improvement Allowance shall be the sole responsibility of
Tenant.

                  23.36. RIGHT OF FIRST REFUSAL. Tenant shall have the on-going
right of first refusal for all or a portion of the First Floor of the Building
that becomes available for lease during the first and second lease years of the
initial Term of this Lease (the "Offered Space"). If Landlord during such period
has a bona fide offer from a third party to lease all or any portion of the
Offered Space, and Landlord is willing to accept such offer, Landlord shall so
notify Tenant in writing. Provided Tenant is not in default of its monetary
obligations hereunder and is not in default of its non-monetary obligations
beyond any applicable cure period hereunder as of the date of Landlord's notice
hereunder, Tenant shall have five (5) business days from the date of Landlord's
notice to advise Landlord that Tenant accepts the Offered Space on the same
terms and conditions set forth in this Lease, except that the Tenant Improvement
Allowance for the Offered Space shall be prorated based on the number of lease
years then remaining in the initial Term, and agrees that the Offered Space
shall become part of the Premises, except the term therefor shall be coterminous
with this Lease. In the event Tenant fails to so notify Landlord within the time
specified, or in the event Tenant is in default of its monetary obligations
hereunder or is in default of its non-monetary obligations beyond any applicable
cure period hereunder as of the date of Landlord's notice hereunder or at any
time during such five (5) business day period thereafter, Landlord shall be
permitted to lease the Offered Space free from any rights of Tenant hereunder.
In the event Tenant exercises its right of first refusal, the Lease shall be
promptly amended in writing to add the Offered Space to the Premises and to
adjust the annual Base Rent and the Tenant's Proportionate Share and to provide
for the Tenant Improvement Allowance for the


                                        3
                                 ADDENDUM NO.1
<PAGE>   61
Offered Space (which amount shall be based on a maximum $20.00 per rentable
square foot of the Offered Space, prorated for the number of lease years then
remaining in the initial Term of the Lease). In the event Tenant exercises its
right to lease the Offered Space by its exercise of its right of first refusal,
the Offered Space shall become part of the Premises, subject to the same terms
and conditions as are contained in this Lease, except as provided in this
Section 23.36. The Offered Space will be delivered to Tenant in its then "as is"
condition and any improvements thereto shall be subject to Landlord's consent;
provided Landlord's consent with respect to non-structural improvements shall
not be unreasonably withheld or delayed. The commencement date for the payment
of Rent with respect to such space shall be the date Landlord delivers
possession of the Offered Space and the term shall end on the last day of the
term of this Lease (as extended or early terminated pursuant to the terms
hereof).

                  23.37. RIGHT OF FIRST OFFER - THE BUILDING. Provided that this
Lease is in full force and effect and Tenant is not in default of its monetary
obligations hereunder and is not in default of its non-monetary obligations
beyond any applicable cure period hereunder, Tenant shall have the on-going
right at any time during the initial Term (subject to the expansion and renewal
rights of other tenants of the Building existing as of the date of this Lease
and further subject to Landlord's right to negotiate renewals of the leases with
said tenants), to lease all or any portion of the Building which becomes
available for leasing. Prior to entering into substantive negotiations with a
prospective tenant for all or any portion of any space becoming available for
lease in the Building, Landlord shall so notify Tenant of the availability of
such space, which notice shall specify the proposed location and size of such
space (the "Available Space") and the proposed commencement date of the lease of
the Available Space (the "Available Space Commencement Date"). Within ten (10)
business days after Tenant's receipt of such notice, Tenant shall give
irrevocable notice to Landlord as to whether or not it desires to lease all or
part of the Available Space and, in the event Tenant desires to lease only a
portion of the Available Space, such notice shall include a description of the
part Tenant desires to lease; provided, however, that the portion of the
Available Space which is not leased by Tenant upon the exercise of this option
must be configured and located so as to be leaseable to third parties in
accordance with customary market terms acceptable to Landlord and the cost of
any necessary demising walls or other construction necessary to render that
portion of the Available Space which is not leased by Tenant leaseable to third
parties (other than tenant improvements) shall be paid by Tenant promptly upon
receipt of Landlord's invoice therefor. If Tenant does not desire to lease all
or any part of the Available Space or Tenant fails to deliver such notice to
Landlord within such ten (10) business day period, Landlord shall have the right
to lease


                                        4
                                 ADDENDUM NO.1
<PAGE>   62
and thereafter to re-let all or any part of the Available Space to a third party
or parties free and clear of any rights of Tenant in such space. If Tenant
exercises its right to lease all or a portion of said Available Space, Landlord
shall deliver the same in its then "as is" condition. If Landlord should lease
the Available Space to a third party, Tenant shall have a right of first offer
on such space if it shall subsequently become available for leasing during the
Term, which right shall be subject to renewals or extensions of the then current
lease of such Available Space.

                  In the event Tenant timely exercises its right to lease the
Available Space, then commencing upon the Available Space Commencement Date,
such space shall become part of the Premises, subject to the same terms and
conditions as are contained in the Lease, except that (i) Tenant's Proportionate
Share shall be adjusted to reflect the addition of said Available Space, (ii)
the Annual Base Rent for the Available Space shall be the then Prevailing Market
rate as determined by Landlord (subject, in the event Tenant disagrees with such
determination, to determination in accordance with the procedures set forth in
Section 23.34 of the Lease) and (iii) the term shall commence on the Available
Space Commencement Date and end on the last day of the Term of the Lease;
provided, that if at the time Tenant exercises its rights under this
subparagraph less than three (3) years remain under the initial Term and said
Available Space consists of 10,000 or more rentable square feet, the Term for
the Premises and the Available Space shall be adjusted to be eight (8) years (or
such longer term as Landlord and Tenant may agree), and provided further, that
if Tenant exercises its rights under this Section 23.37 during the first (1st)
through the eighth (8th) lease years of the initial Term, Tenant shall also be
entitled to a Tenant Improvement Allowance of $15.00 per rentable square foot
(the "Available Space Tenant Improvement Allowance"). The improvements to be
constructed in the Available Space shall be designed and constructed in
accordance with the applicable procedures set forth in Exhibit C. Any costs
incurred by Tenant in excess of the foregoing Available Space Tenant Improvement
Allowance shall be the sole responsibility of Tenant. Landlord and Tenant shall
execute an amendment to Lease, which shall have been prepared by Landlord and
shall be in form and substance reasonably satisfactory to Landlord and Tenant,
confirming the adjustments to the Premises, Tenant's Proportionate Share, and
the Rent in connection with Tenant's exercise of its right of first offer
hereunder.

                  23.38. PARKING FINANCING CONTINGENCY. This Lease and the
obligations of Landlord and Tenant hereunder are expressly contingent upon St.
Louis Parking's receipt of a commitment for a loan on terms no less favorable to
St. Louis Parking than those set forth below for the construction of a new
parking garage to be constructed by St. Louis Parking at the intersection of
Lucas and Broadway.

                Loan Amount:                     $8,000,000.00

                Interest Rate:                   7.5% per annum

                Amortization                     25 years


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                                 ADDENDUM NO.1
<PAGE>   63
This contingency shall be automatically satisfied without any further action by
Landlord or Tenant hereunder upon St. Louis Parking's receipt of a financing
commitment containing the foregoing minimum terms. In the event St. Louis
Parking shall not have received such commitment on or prior to February 28,
2001, Tenant may effect the termination of this Lease only by delivery of a
written notice of termination to Landlord on or prior to 12:00 noon St. Louis
time, on March 1, 2001. In the event Tenant fails to deliver such notice of
termination, this contingency shall be deemed to be satisfied.


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                                 ADDENDUM NO.1