Document:

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                                                                   Exhibit 10.5

                             AMENDED AND RESTATED
                             EMPLOYMENT AGREEMENT

            THIS AMENDED AND RESTATED EMPLOYMENT AGREEMENT (this "AGREEMENT")
effective as of June 1, 2001, between Dade Behring, Inc., a Delaware
corporation (the "COMPANY"), and James Reid-Anderson ("EXECUTIVE").

            The Company and Executive have entered into an Employment
Agreement effective as of September 1, 2000 (the "ORIGINAL AGREEMENT") and
desire to amend and restate the Original Agreement in its entirety pursuant
to the terms and conditions set forth in this Agreement.

            The Company is a wholly-owned subsidiary of Dade Behring
Holdings, Inc., a Delaware corporation ("HOLDING").

            In consideration of the mutual covenants contained herein and
other good and valuable consideration, the receipt and sufficiency of which
are hereby acknowledged, the parties hereto agree to amend and restated the
Original Agreement as follows:

            1.    EMPLOYMENT. The Company shall employ Executive, and
Executive hereby accepts employment with the Company, upon the terms and
conditions set forth in this Agreement for the period beginning on June 1,
2001 and ending as provided in paragraph 4 hereof (the "EMPLOYMENT PERIOD").

            2.    POSITION AND DUTIES.

            (a) During the Employment Period, Executive shall serve as the
President and Chief Executive Officer of the Company and shall have the
normal duties, responsibilities and authority of the President and Chief
Executive Officer, subject to the overall direction and authority of the
Board of Directors. In addition, so long as he is Chief Executive Officer of
Holding, the Executive shall be appointed to the board of directors of
Holding and the board of directors of the Company (so long as the Company
remains the principal operating subsidiary of Holding). At the time he ceases
to be the Chief Executive Officer of Holding, Executive shall resign from the
board of directors of Holding.

            (b) Executive shall report to the Board of Directors, and
Executive shall devote his best efforts and his full business time and
attention to the business and affairs of the Company and its Subsidiaries;
provided, that nothing in this paragraph 2(b) shall prohibit Executive from
devoting a reasonable amount of business time and attention to directorships
and charitable or other activities.

            (c) For purposes of this Agreement, "SUBSIDIARIES" shall mean any
corporation of which the securities having a majority of the voting power in
electing directors are, at the time of determination, owned by the Company,
directly or through one or more Subsidiaries.

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            3.    BASE SALARY AND BENEFITS.

            (a) During the Employment Period, Executive's base salary shall
be $725,000 per annum and shall be subject to review by the Board of
Directors on an annual basis (the "BASE SALARY"), which salary shall be
payable in regular installments in accordance with the Company's general
payroll practices and shall be subject to customary withholding. In addition,
during the Employment Period, Executive shall be entitled to participate in
all of the Company's employee benefit programs for which senior executive
employees of the Company and its Subsidiaries are generally eligible;
provided, however, that for purposes of determining Executive's participation
in the Company's cash balance pension program, Executive's benefits shall be
accrued as though he had two years of service for every one year of total
service that otherwise would be included in the computation of such benefits.

            (b) The Company shall reimburse Executive for all reasonable
expenses incurred by him in the course of performing his duties under this
Agreement which are consistent with the Company's policies in effect from
time to time with respect to travel, entertainment and other business
expenses, subject to the Company's reasonable requirements with respect to
reporting and documentation of such expenses.

            (c) In addition to the Base Salary, during each year during the
Employment Period commencing with the fiscal year ending December 31, 2001,
Executive will be eligible to earn an annual target bonus of 100% of his Base
Salary to be based upon specific bonus targets to be established on an annual
basis by the Board (with specific overachievement opportunities to be made
available in the sole discretion of the Board); provided that with respect to
the fiscal year ending December 31, 2001, Executive's bonus shall be a
minimum of $1,000,000. Such bonus targets will generally focus on EBITDA,
capital expenditure levels and working capital targets, as established on an
annual basis by the Board. Any bonus shall be payable in accordance with
normal Company policy, but in no event later than March 15 of any particular
year.

            (d) In addition to Executive's participation in the Company's
current retention program, Executive will receive an incremental retention
bonus of $350,000 on the date of this Agreement and will be eligible for an
incremental retention bonus of $1,000,000, to be based upon the achievement
of specified objectives and to be paid at the times set forth in EXHIBIT A
attached hereto.

            (e) In addition, Executive will be entitled to (i) four (4) weeks
paid vacation each year during the Employment Period, in accordance with
Company policy, (ii) an annual sum of $24,000, payable monthly, as an
allowance to cover expenses for the use of Executive's own automobile for
business purposes, and (iii) reimbursement (including an appropriate tax
gross-up) for business class family leave travel and personal financial and
legal consulting expense reimbursement in line with Company's senior
executive program.

            (f) Executive will be considered for grants of stock options by
Holding for which senior executive employees of the Company and its
Subsidiaries are generally eligible, which grants will be at sole discretion
of the Board; provided, however, that the confirmed plan of reorganization

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(or consensual agreement in the case of an out of court reorganization) will
contain an equity incentive program for Executive, so long as Executive is
employed by the Company at the time of such reorganization (it being
understood that the sole remedy for breach of this Section 3(f) shall be
Executive's right to terminate the Employment Period for Good Reason).

            4.    TERM.

            (a) The Employment Period (i) shall terminate upon Executive's
resignation without Good Reason (as defined below), death or Disability (as
defined below), (ii) may be terminated by the Company at any time for Cause
(as defined below) or without Cause and (iii) may be terminated upon
Executive's resignation for Good Reason.

            (b) If the Employment Period is terminated by the Company without
Cause or by Executive for Good Reason during the term of this Agreement,
Executive shall be entitled to:

      (i)   an amount equal to (x) two times Executive's Base Salary described
            in Section 3(a) above (as in effect at the time of such
            termination), plus (y) two times Executive's target bonus for the
            year in which Executive is terminated (provided that in the case of
            calendar year 2001 the aggregate amount payable under clause (y)
            shall be $1,725,000), in each case payable not later than 30 days
            following the date of such termination; and

      (ii)  receive the benefits described in Sections 3(e)(ii) and 3(e)(iii)
            above and participate in the Company's health program for which
            senior executive employees of the Company and its Subsidiaries are
            generally eligible, in each case, for 24 months after the date of
            such termination.

If the Employment Period is terminated due to Executive's death or Disability
during the term of this Agreement, Executive shall be entitled to receive a
bonus equal to the bonus Executive would had received had he remained
employed for the entire bonus period (the amount to be determined by the
Board in good faith), pro rated based on the number of days that have elapsed
during the year through the date of termination (and payable in accordance
with normal Company policy). Notwithstanding anything in this Agreement to
the contrary, the Company shall have no obligation to provide the benefits
under Section 4(b)(ii) of this Agreement during such times as Executive is in
material breach of any provision of this Agreement (including, without
limitation, that certain Amended and Restated Employment Agreement Addendum
dated as of September 1, 2000 between the Company and Executive (the
"EMPLOYMENT AGREEMENT ADDENDUM")) or any provision of the Executive Agreement
dated as of October 1, 1997 between Holding and Executive (the "EXECUTIVE
AGREEMENT"). As a condition to the Company's obligations (if any) to make
severance payments pursuant to this paragraph 4(b), Executive will execute
and deliver a general release in form and substance satisfactory to the
Company, except that the Company shall be obligated to pay amounts due and
owing to Executive as expressly provided by this Agreement. In addition to
the amounts described above, in the event the Employment Period is terminated
by the Company without Cause, by Executive for Good Reason or due to
Executive's death or Disability, with respect to any time- based stock
options issued to Executive by Holding, the date of Executive's termination
for purposes

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of all vesting schedules shall be deemed to have occurred immediately after
the next succeeding vesting date. Notwithstanding anything in Holding's
option plans to the contrary, solely in the case of Executive's death or
Disability, the exercise period for each of Executive's options shall be
extended to the earlier of (x) the 12-month anniversary of the date of
termination of Executive's employment, and (y) the date on which each such
option otherwise would have expired had Executive remained employed with the
Company (including, without limitation, any acceleration event required by
the plan such as a change in control event).

            (c) If the Employment Period is terminated by the Company for
Cause or is terminated pursuant to clause (a)(i) above, Executive shall be
entitled to receive his Base Salary through the date of termination.

            (d) Except as otherwise provided in this Agreement, all of
Executive's rights to fringe benefits and bonuses hereunder (if any) which
accrue or become payable after the termination of the Employment Period shall
cease upon such termination; provided, however, that if the Employment Period
is terminated by the Company without Cause or by Executive for Good Reason
after December 31 of a particular year (and Executive was employed as of
December 31 of such year), but prior to the date on which the bonus described
in Section 3(c) of this Agreement for such year, if any, is payable, then
Executive shall be paid such bonus at the time set forth in Section 3(c) of
this Agreement (it being understood that the determination of whether a bonus
is payable shall be made in accordance with the provisions of Section 3(c) of
this Agreement), which bonus payment, if any, shall be in addition to any
severance payments otherwise payable under this Agreement. The Company may
offset any amounts Executive owes it or its Subsidiaries against any amounts
it owes Executive hereunder.

            (e) For purposes of this Agreement, "DISABILITY" (i) shall mean
any physical or mental incapacitation which results in Executive's inability
to perform his duties and responsibilities for the Company for a total of 180
days during any twelve-month period, as determined by the Board in its good
faith judgment and (ii) shall be deemed to have occurred on the 180th day of
such inability to perform.

            (f) For purposes of this Agreement, "CAUSE" shall mean (i) the
intentional disregard of a written direction from the Board of Directors to
Executive to which Executive has not objected within ten (10) business days
of receiving such written direction, which intentional disregard is
materially injurious to the Company or any of its affiliates, (ii) the
knowing and intentional theft by Executive of property of the Company or any
of its affiliates, which property has a substantial value, (iii) the
commission by Executive of an act of moral turpitude which is materially
injurious to the Company or any of its affiliates or (iv) any material breach
of this Agreement (including, without limitation, the Employment Agreement
Addendum) or any material breach of the Executive Agreement.

            (g) For purposes of this Agreement, "GOOD REASON" shall mean (i)
any substantial reduction of Executive's duties, without Executive's written
consent, (ii) a reduction by the Company of Executive's Base Salary, as in
effect on the date hereof or as the same may be increased from time to time,
(iii) the Executive's removal (without his consent) from the board of
directors of

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Holding or the board of directors of the Company (so long as the Company
remains the principal operating subsidiary of Holding), (iv) the Executive
being required, without his consent, to move his primary place of business
outside of the greater Chicago area, (v) the Company shall have failed to
make a legitimate proposal to Executive on or before June 30, 2002 for an
equity incentive program for Executive to take effect upon the reorganization
of the Company, (vi) the Company and Executive are unable to reach agreement
(including complete documentation) regarding the terms of a satisfactory
equity incentive program for Executive to take effect upon the reorganization
of the Company prior to the earlier of (x) September 30, 2002; provided,
however that if the Company and Executive are actively negotiating the
documentation thereof at that time, then such September 30, 2002 date shall
be extended to December 31, 2002, and (y) 30 days after the effective date of
the confirmed plan of reorganization (or effective date of a consensual
agreement in the case of an out of court reorganization) (so long as
Executive has given serious consideration to any such proposals for an equity
incentive program), (vii) any breach of this Agreement (including the failure
to make available any of the benefits described in Section 3 of this
Agreement on the terms set forth therein, including bonuses) or the Company's
obligations to Executive under the Company's retention bonus program, other
than insignificant or immaterial breaches, (viii) the failure of the Company
to obtain promptly (but in any event on or prior to July 23, 2001) from its
senior lenders any consents required under the terms of its senior secured
credit facility by virtue of the Company's execution and delivery of this
Agreement, (ix) the failure of any final debtor-in-possession financing order
entered in a Chapter 11 case filed by or against the Company (the "Chapter 11
Case") or any of its affiliates to contain a "carve out" provision whereby
the financial obligations of the Company hereunder to Executive (whether or
not such obligations, but for such order, would be allowed obligations of the
estate) would have a priority over any liens, security interests and claims
of the debtor-in-possession lenders (regardless of whether this Agreement has
been assumed or not assumed by the debtor-in- possession), provided that
neither the carve out contemplated hereby nor the payments thereunder shall
effect a reduction of, or a deduction from, the dollar amount of the claims
of the debtor-in- possession lenders, or (x) the failure of an order to be
entered authorizing the assumption of this Agreement within 60 days after the
entry of an order for relief in the Chapter 11 Case.

            (h) Executive shall have the benefit of indemnification for acts
undertaken on behalf of the Company to the fullest extent provided under the
Company's bylaws and the laws of the State of Delaware. In addition, the
Company agrees to maintain D&O insurance coverage during the Employment
Period for the benefit of Executive, in amounts not less than the coverage in
effect on the date hereof. In addition, the Company shall provide
supplemental disability coverage under the same co-payment conditions as the
Company's group plan for Executive such that his aggregate annual disability
benefit from the Company is equal to (x) 70% of his most recent base salary,
plus (y) his annual target bonus.

            5.    EMPLOYMENT AGREEMENT ADDENDUM. Each of the parties hereto
acknowledges and agrees that the Employment Agreement Addendum which is
attached hereto and is made a part hereof is an integral part of this
Agreement and that the Company would not be willing to enter into this
Agreement and provide Executive with the substantial benefits provided herein
without Executive's agreement to enter into and become bound by the terms and
conditions of the Employment Agreement Addendum, including the Conflict of
Interest, Confidentiality, Non- Competition and Intellectual Property Rights
provisions thereof.

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            6.    EXECUTIVE'S REPRESENTATIONS. Executive hereby represents
and warrants to the Company that (i) the execution, delivery and performance
of this Agreement by Executive does not and will not conflict with, breach,
violate or cause a default under any contract, agreement, instrument, order,
judgment or decree to which Executive is a party or by which he is bound,
(ii) Executive is not a party to or bound by any employment agreement,
noncompete agreement or confidentiality agreement with any other person or
entity and (iii) upon the execution and delivery of this Agreement by the
Company, this Agreement shall be the valid and binding obligation of
Executive, enforceable in accordance with its terms. Executive hereby
acknowledges and represents that he has consulted with independent legal
counsel regarding his rights and obligations under this Agreement and that he
fully understands the terms and conditions contained herein.

            7.    SURVIVAL. The terms and conditions of the Employment
Agreement Addendum shall survive and continue in full force in accordance
with their terms notwithstanding any termination of the Employment Period.

            8.    NOTICES. Any notice provided for in this Agreement shall be
in writing and shall be either personally delivered, sent by reputable
overnight courier or mailed by first class mail, return receipt requested, to
the recipient at the address below indicated:

            NOTICES TO EXECUTIVE:

            James Reid-Anderson
            1160 North Sheridan Road
            Lake Forest, IL 60045

            WITH A COPY TO:

            Altheimer & Gray
            Suite 4000, 10 South Wacker Drive
            Chicago, Illinois 60606
            Attn: Phillip Gordon

            NOTICES TO THE COMPANY:

            Dade Behring, Inc.
            1717 Deerfield Road
            Deerfield, Illinois 60015
            Attn: Steven Barnes
                  John Connaughton
                  Robert Luse

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            WITH A COPY TO:

            Kirkland & Ellis
            200 East Randolph Drive
            Chicago, Illinois  60601
            Attn: Matthew E. Steinmetz

or such other address or to the attention of such other person as the
recipient party shall have specified by prior written notice to the sending
party. Any notice under this Agreement shall be deemed to have been given
when so delivered, deposited with such courier or mailed.

            9.    SEVERABILITY. Whenever possible, each provision of this
Agreement shall be interpreted in such manner as to be effective and valid
under applicable law, but if any provision of this Agreement is held to be
invalid, illegal or unenforceable in any respect under any applicable law or
rule in any jurisdiction, such invalidity, illegality or unenforceability
shall not affect any other provision or any other jurisdiction, but this
Agreement shall be reformed, construed and enforced in such jurisdiction as
if such invalid, illegal or unenforceable provision had never been contained
herein.

            10.   COMPLETE AGREEMENT. This Agreement, those documents
expressly referred to herein (including the Employment Agreement Addendum)
and other documents of even date herewith embody the complete agreement and
understanding among the parties and supersede and preempt any prior
understandings, agreements or representations by or among the parties,
written or oral, which may have related to the subject matter hereof in any
way.

            11.   NO STRICT CONSTRUCTION. The language used in this Agreement
shall be deemed to be the language chosen by the parties hereto to express
their mutual intent, and no rule of strict construction shall be applied
against any party.

            12.   COUNTERPARTS. This Agreement may be executed in separate
counterparts, any one of which may be by facsimile and each of which is
deemed to be an original and all of which taken together constitute one and
the same agreement.

            13.   SUCCESSORS AND ASSIGNS. This Agreement is intended to bind
and inure to the benefit of and be enforceable by Executive, the Company and
their respective heirs, successors and assigns, except that Executive may not
assign his rights or delegate his obligations hereunder without the prior
written consent of the Company.

            14.   CHOICE OF LAW. ALL ISSUES AND QUESTIONS CONCERNING THE
CONSTRUCTION, VALIDITY, ENFORCEMENT AND INTERPRETATION OF THIS AGREEMENT AND
THE EXHIBITS AND SCHEDULES HERETO SHALL BE GOVERNED BY, AND CONSTRUED IN
ACCORDANCE WITH, THE LAWS OF THE STATE OF ILLINOIS, WITHOUT GIVING EFFECT TO
ANY CHOICE OF LAW OR CONFLICT OF LAW RULES OR PROVISIONS (WHETHER OF THE
STATE OF ILLINOIS OR ANY OTHER JURISDICTION) THAT WOULD CAUSE THE APPLICATION
OF THE LAWS OF ANY JURISDICTION OTHER THAN THE STATE OF ILLINOIS.

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            15.   ARBITRATION. Any dispute or controversy arising under or in
connection with this Agreement or the Employment Agreement Addendum shall be
settled exclusively by binding arbitration in Chicago, Illinois in accordance
with the Rules of Endispute/JAMS then in effect. An arbitrator reasonably
acceptable to the Company and the Executive shall preside over any
arbitration; PROVIDED that if the Company and the Executive are unable, in
good faith, to agree on an arbitrator, each will nominate an arbitrator and
such nominated arbitrators will elect a third arbitrator. If Executive brings
an action and successfully enforces his rights under this Agreement or the
Company brings an action and successfully enforces its rights under the
Employment Agreement Addendum, such party shall be entitled to its reasonable
attorneys' fees and costs, as determined by the arbitrator. In any event, the
Company shall bear the costs of the arbitrators. In addition, Executive shall
be entitled to reimbursement for reasonable attorneys' fees associated with
the preparation and negotiation of this Agreement and the other agreements
contemplated hereby.

            16.   FURTHER ASSURANCES. The Company and Executive,
respectively, will execute and deliver such further documents and take such
additional actions as the other party may reasonably request to effect,
consummate, confirm or evidence the matters contemplated by this Agreement.

            17.   AMENDMENT AND WAIVER. The provisions of this Agreement may
be amended or waived only with the prior written consent of the Company and
Executive, and no course of conduct or failure or delay in enforcing the
provisions of this Agreement shall affect the validity, binding effect or
enforceability of this Agreement.

                             *    *    *    *    *

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

                                      DADE BEHRING, INC.

                                      By:   /s/ Steven W. Barnes
                                            ------------------------------------
                                      Its:  Vice President & Assistant Secretary
                                            ------------------------------------
                                      By:   /s/ Lawrence A. Rosen
                                            ------------------------------------
                                      Its:  Authorized Representative
                                            ------------------------------------

                                      /s/ James Reid-Anderson
                                      ---------------------------------
                                      JAMES REID-ANDERSON

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                                   EXHIBIT A

                Terms of Incremental $1,000,000 Retention Bonus

Executive shall be entitled to receive the following incremental retention
payments, so long as Executive is actively employed by the Company on the
date the payment is to be made:

            Eligible Portion of $333,333 will be paid to Executive at the time
            of a successful financial restructuring of the Company or December
            1, 2001, whichever is earlier.

            Eligible Portion of $333,333 will be paid to Executive six months
            after the successful financial restructuring of the Company but,
            consistent with the existing retention program, no later than April
            1, 2003.

            Eligible Portion of $333,334 will be paid to Executive on April 1,
            2003.

"Eligible Portion" shall mean the sum of the following percentages:

            33-1/3%, so long as:

                    (x)  in the case of the first scheduled payment, the Company
                         has as of the date of such payment begun implementation
                         of a cost reduction program with an annual run rate
                         savings potential totaling $30 million (i.e., Monarch
                         II); provided, however, that if as of the date of such
                         payment the Company has not yet launched the Monarch II
                         program, then in the case of the first scheduled
                         payment, the Eligible Portion shall be determined
                         solely on the basis of achievement of the EBITDA
                         targets set forth in the Company's DIP forecast and
                         Long- Term Business Plan delivered to the Company's
                         senior bank group dated April 2001, respectively, with
                         each measurement weighted 50%,

                    (y)  in the case of the second scheduled payment, the
                         Company has as of the date of such payment begun
                         implementation of the Monarch II program, or

                    (z)  in the case of the third scheduled payment, the Company
                         has as of the date of such payment completed
                         implementation of the Monarch II program and has
                         realized cost savings at an annual run rate of $30
                         million.

            33-1/3%, so long as the Company has achieved the EBITDA targets set
            forth in the Company's DIP forecast.

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            33-1/3%, so long as the Company has achieved the EBITDA targets set
            forth in the Company's Long-Term Business Plan delivered to the
            Company's senior bank group dated April 2001.

The percentages above that relate to the achievement of EBITDA targets shall
be based upon the Company's performance for the four calendar quarters ending
as of the last day of the calendar quarter immediately preceding the date a
retention bonus is to be paid.

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                                                                   Exhibit 10.6

                                 LEASE AGREEMENT

                                     BETWEEN

                  PRENTISS PROPERTIES REAL ESTATE FUND I, L.P.
                         A DELAWARE LIMITED PARTNERSHIP

                                   (LANDLORD)

                                       AND

                               DADE BEHRING INC.,
                             A DELAWARE CORPORATION

                                    (TENANT)

                               1717 DEERFIELD ROAD
                               DEERFIELD, ILLINOIS

                             DATED: JANUARY 28, 2000

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                                TABLE OF CONTENTS

ARTICLE                                                                   PAGE
-------                                                                   ----

1        BASIC LEASE INFORMATION AND CERTAIN DEFINITIONS.....................1

2        PREMISES AND QUIET ENJOYMENT........................................3

3        TERM; COMMENCEMENT DATE; DELIVERY AND ACCEPTANCE OF PREMISES........4

4        RENT................................................................4

5        OPERATING COSTS.....................................................5

6        INTENTIONALLY DELETED...............................................8

7        SERVICES OF LANDLORD................................................8

8        ASSIGNMENT AND SUBLETTING..........................................10

9        REPAIRS............................................................13

10       ALTERATIONS........................................................14

11       LIENS..............................................................16

12       USE AND COMPLIANCE WITH LAWS.......................................16

13       DEFAULT AND REMEDIES...............................................17

14       INSURANCE..........................................................19

15       DAMAGE BY FIRE OR OTHER CAUSE......................................21

16       CONDEMNATION.......................................................22

17       INDEMNIFICATION....................................................23

18       SUBORDINATION AND ESTOPPEL CERTIFICATES............................24

19       SURRENDER OF THE PREMISES..........................................26

20       LANDLORD'S RIGHT TO INSPECT........................................27

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21       ROOF SPACE.........................................................27

22       BROKERAGE..........................................................28

23       OBSERVANCE OF RULES AND REGULATIONS................................28

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

25       MISCELLANEOUS......................................................29

26       EXTENSION OPTION...................................................32

27       OTHER DEFINITIONS..................................................34

28       WAIVER OF TRIAL BY JURY............................................35

                                                                               3
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                               EXHIBITS AND RIDERS

      The following Exhibits and Riders are attached hereto and by this
reference made a part of this Lease:

EXHIBIT A      -     THE LAND

EXHIBIT B      -     RENT SCHEDULE

EXHIBIT C      -     FORM OF COMMENCEMENT DATE

RIDER NO. 1    -     RULES AND REGULATIONS

                                                                               4
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                                 LEASE AGREEMENT

      THIS LEASE AGREEMENT ("this Lease") is made and entered into by and
between Prentiss Properties Real Estate Fund I, L.P., a Delaware limited
partnership ("Landlord"), and Dade Behring Inc., a Delaware corporation
("Tenant"), upon all the terms set forth in this Lease and in all Exhibits and
Riders hereto, to each and all of which terms Landlord and Tenant hereby
mutually agree, and in consideration of One Dollar ($1.00) and other valuable
consideration, the receipt and sufficiency of which are hereby acknowledged, and
of the rents, agreements and benefits flowing between the parties hereto, as
follows:

                                    ARTICLE 1

                BASIC LEASE INFORMATION AND CERTAIN DEFINITIONS

      Section 1.1 Each reference in this Lease to information and definitions
contained in the Basic Lease Information and Certain Definitions and each use of
the terms capitalized and defined in this Section 1.1 shall be deemed to refer
to, and shall have the respective meaning set forth in, this Section 1.1.

A.    Premises:                          The Land, the Building and the other
                                         improvements located on the Land.

B.    Building:                          The building located generally at
                                         1717 Deerfield Road, Deerfield,
                                         Illinois.

C.    Land:                              That certain parcel of real estate
                                         described in Exhibit A attached
                                         hereto.

D.    Commencement Date:                 April 1, 2000

E.    Expiration Date:                   March 31, 2012

F.    Term:                              Twelve (12) Lease Years.  The first
                                         "Lease Year" shall be the period
                                         from the Commencement Date to the
                                         last day of the twelfth (12th) full
                                         calendar month following the
                                         calendar month in which the
                                         Commencement Date occurs.
                                         Thereafter, each consecutive twelve
                                         (12) calendar month period shall
                                         constitute one (1) Lease Year.
                                         Notwithstanding anything contained
                                         herein to the contrary, if the
                                         Commencement Date occurs on the
                                         first (1st) day of a calendar month,
                                         the first Lease Year shall be twelve
                                         (12) full calendar months.

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G.    Rentable Area of the Building:     Landlord and Tenant agree that for
                                         all purposes of this Lease the
                                         Rentable Area of the Building shall
                                         be deemed to be 137,904 square feet.

H.    Tenant's Share:                    One Hundred Percent (100%).

I.    Rent:                              The Base Rent and the Additional
                                         Rent.

J.    Base Rent:                         The Base Rent shall be the amounts
                                         set forth on the Base Rent Schedule
                                         attached hereto as Exhibit B,
                                         subject to such increases as may be
                                         provided herein.

K.    Additional Rent:                   The Additional Rent shall be all
                                         other sums due and payable by Tenant
                                         under the Lease, including, but not
                                         limited to, Tenant's Share of Operating
                                         Costs.

L.    Tenant's Permitted Uses:           Tenant may use the Premises for
                                         general office use and for other
                                         purposes ancillary to general office
                                         use (for example an employee
                                         cafeteria).

M.    Brokers:                           Gibraltar Real Estate Services
                                         Corporation (Tenant) and Prentiss
                                         Properties Limited, Inc. (Landlord)

N.    Landlord's Address for Notice:     Prentiss Properties Real Estate Fund
                                         I, L.P.
                                         3890 W. Northwest Highway, Suite 400
                                         Dallas, Texas  75220
                                         Attention: President

                                         With a copy to:

                                         Prentiss Properties Management, L.P.
                                         One O'Hare Centre
                                         6250 North River Road, Suite 1010
                                         Rosemont, Illinois  60018
                                         Attention: Property Manager

                                         - and -

                                                                               6
<PAGE>

                                         Prentiss Properties Limited, Inc.
                                         One O'Hare Centre
                                         6250 North River Road, Suite 1010
                                         Rosemont, Illinois  60018
                                         Attention:  Managing Director

U.    Landlord's Address for Payment:    Prentiss Properties Real Estate Fund
                                         I, L.P.
                                         P.O. Box 70776
                                         Chicago, Illinois  60673

V.    Tenant's Address for Notice:       Dade Behring Inc.
                                         1717 Deerfield Road
                                         Deerfield, Illinois  60015
                                         Attn:  Facilities Manager

      with a copy to:                    General Counsel
                                         Dade Behring Inc.
                                         1717 Deerfield Road
                                         Deerfield, Illinois  60015

                                    ARTICLE 2

                          PREMISES AND QUIET ENJOYMENT

      Section 2.1 Landlord hereby leases the Premises to Tenant, and Tenant
hereby rents and hires the Premises from Landlord, for the Term. Tenant shall be
subject to the terms and conditions of any Declaration of Covenants, Conditions
and Restrictions (the "Declaration") which may now, or in the future, may be
filed of record in the Deed Records of Lake, County, Illinois, including any
amendments to any of the foregoing documents, so long as any such Declarations
or amendments do not interfere with Tenant's use or quiet enjoyment of the
Premises. The list of all such Declarations is attached hereto as Schedule 2.1.

      Section 2.2 Provided that Tenant fully and timely performs all the terms
of this Lease on Tenant's part to be performed, including payment by Tenant of
all Rent, Tenant shall have, hold and enjoy the Premises during the Term without
hindrance or disturbance from or by Landlord or any third party by or through
Landlord; subject, however, to all of the terms, conditions and provisions of
any and all ground leases, deeds to secure debt, mortgages, restrictive
covenants, easements, and other encumbrances now or hereafter affecting the
Premises.

                                                                               7
<PAGE>
                                    ARTICLE 3

                            TERM; COMMENCEMENT DATE;
                       DELIVERY AND ACCEPTANCE OF PREMISES

      Section 3.1 The Commencement Date shall be April 1, 2000.

      Section 3.2 INTENTIONALLY DELETED.

      Section 3.3 By written instrument substantially and materially in the form
of Exhibit C attached hereto, Landlord shall notify Tenant of the Commencement
Date and all other matters stated therein. Such Commencement Notice shall be
conclusive and binding on Tenant as to all matters set forth therein, unless
within ten (10) Business Days following delivery of such Commencement Notice,
Tenant contests any of the matters contained therein by notifying Landlord in
writing of Tenant's objections. The foregoing notwithstanding, Landlord's
failure to deliver any Commencement Notice to Tenant shall not affect Landlord's
determination of the Commencement Date.

      Section 3.4 INTENTIONALLY DELETED.

      Section 3.5 Subject to the provision of Article 6 hereof, Tenant agrees to
accept the Premises in their current "as-is" condition. Subject to the
provisions of Article 6 hereof, occupancy of the Premises or any portion thereof
by Tenant or anyone claiming through or under Tenant shall be conclusive
evidence that Tenant and all parties claiming through or under Tenant (a) have
accepted the Premises or such portion as suitable for the purposes for which the
Premises are leased hereunder and the needs of Tenant, and (b) have waived any
defects in the Premises. Landlord shall have no liability, except for gross
negligence or willful misconduct, to Tenant or any of Tenant's agents,
employees, licensees, servants or invitees for any injury or damage to any
person or property due to the condition or design of, or any defect in, the
Premises, including any electrical, plumbing or mechanical systems and equipment
of the Premises and the condition of or any defect in the Land; and Tenant, for
itself and its agents, employees, licensees, servants and invitees, expressly
assumes all risks of injury or damage to person or property, either proximate or
remote, resulting from the condition of the Premises.

                                    ARTICLE 4

                                      RENT

      Section 4.1 Tenant shall pay to Landlord, without notice, demand, offset
or deduction, in lawful money of the United States of America, at Landlord's
Address for Payment, or at such other place as Landlord shall designate in
writing from time to time: (a) the Base Rent in equal monthly installments, and
(b) the Additional Rent in installments in the amounts determined pursuant to
Article 5 below, in advance, on the first day of each calendar month during the
Term. The first monthly installment of Base Rent and the Additional Rent payable
under Article 5 hereof shall be

                                                                               8
<PAGE>

paid in advance on the date of Tenant's execution of this Lease and applied to
the first installments of Base Rent and Additional Rent coming due under this
Lease. Payment of Rent shall begin on the Commencement Date; provided, however,
that, if either the Commencement Date or the Expiration Date falls on a date
other than the first day of a calendar month, the Rent due for such fractional
month shall be prorated on a per diem basis between Landlord and Tenant so as to
charge Tenant only for the portion of such fractional month falling within the
Term.

      Section 4.2 All past due installments of Rent shall be subject to a late
charge of two and one half percent (2.5%) of the amount of the late payment and
shall further bear interest until paid at a rate per annum (the "Interest Rate")
equal to the greater of fifteen percent (15%) or four percent (4%) above the
prime rate of interest from time to time publicly announced by BankOne, a
national banking association, or any successor thereof; provided, however, that,
if at the time such interest is sought to be imposed the rate of interest
exceeds the maximum rate permitted under federal law or under the laws of the
State of Illinois, the rate of interest on such past due installments of Rent
shall be the maximum rate of interest then permitted by applicable law; and
further provided that as to the first two (2) instances in any consecutive
twelve (12) month period during the Term, the aforesaid late charge and Interest
Rate shall not apply unless and until said past due installment is more than
five (5) days past due.

                                    ARTICLE 5

                                 OPERATING COSTS

      Section 5.1 Concurrently with the first payment of Base Rent hereunder and
on the first day of each calendar month during the Term, Tenant shall pay to
Landlord, as Additional Rent, an amount ("Tenant's Operating Costs Payment") of
money equal to Tenant's Share of Operating Costs, for each year or fractional
year during the Term, such amount to be calculated and paid as follows:

            A. Within sixty (60) days following the Commencement Date and during
the term of the Agreement, on each December 1 of the year prior to the year in
which the Tenant's Operating Costs Payment are due, Landlord shall furnish
Tenant with a statement ("Landlord's Operating Costs Estimate") setting forth
Landlord's reasonable estimate of Operating Costs for the forthcoming year and
Tenant's Operating Costs Payment for such year. On the first day of each
calendar month during such year, Tenant shall pay to Landlord one-twelfth
(1/12th) of Tenant's Operating Costs Payment as estimated on Landlord's
Operating Costs Estimate. If during any calendar year actual Operating Costs
differ from Landlord's Operating Costs Estimate for such calendar year, Landlord
may send Tenant a revised Landlord's Operating Costs Estimate, and, upon receipt
thereof, Tenant shall thereafter make monthly payments as set forth in the
revised Landlord's Operating Cost Estimate; provided that Landlord may not make
such a revision more than once in any calendar year. If for any reason Landlord
has not provided Tenant with Landlord's Operating Costs Estimate on the first
day of January of any year during the Term, then (a) until the first day of the
calendar month following the month in which Tenant is given Landlord's Operating
Costs Estimate, Tenant shall continue to pay to Landlord on the first day of
each calendar month the sum, if any, payable by Tenant under this Section 5.1
for the month of December of the preceding year, and (b) promptly after
Landlords' Operating Costs Estimate is furnished to Tenant, Landlord shall

                                                                               9
<PAGE>

give notice to Tenant stating whether the installments of Tenant's Operating
Costs Payments previously made for such year were greater or less than the
installments of Tenant's Operating Costs Payments to be made for such year, and
(i) if there shall be a deficiency, Tenant shall pay the amount thereof to
Landlord within thirty (30) days after the delivery of Landlord's Operating
Costs Estimate, or (ii) if there shall have been an overpayment, Landlord shall
apply such overpayment as a credit against the next accruing monthly
installment(s) of Tenant's Operating Costs Payment due from Tenant until fully
credited to Tenant, and (iii) on the first day of the calendar month following
the month in which Landlord's Operating Costs Estimate is given to Tenant and on
the first day of each calendar month throughout the remainder of such year,
Tenant shall pay to Landlord an amount equal to one-twelfth (1/12th) of Tenant's
Operating Costs Payment.

            B. On the last day of March of each year during the Term (beginning
on the last day of March of the first year following the year in which the
Commencement Date occurs), or as soon thereafter as is practicable, Landlord
shall furnish Tenant with a statement of the actual Operating Costs for the
preceding year. Within thirty (30) days after Landlord's giving of such
statement, Tenant shall make a lump sum payment to Landlord in the amount, if
any, by which Tenant's Operating Costs Payment for such preceding year as shown
on such Landlord's statement, exceeds the aggregate of the monthly installments
of Tenant's Operating Costs Payments paid during such preceding year. If
Tenant's Operating Costs Payment, as shown on such Landlord's statement, is less
than the aggregate of the monthly installments of Tenant's Operating Costs
Payment actually paid by Tenant during such preceding year, then Landlord shall
apply such amount to the next accruing monthly installment(s) of Tenant's
Operating Costs Payment due from Tenant until fully credited to Tenant. Tenant
shall have the right upon the delivery of written notice to Landlord ("Tenant's
Review Notice") and at reasonable times to review the books and records of
Landlord relating to Tenant's Operating Costs Payment. Such review shall take
place at the office of Landlord's managing agent and shall be at Tenant's sole
cost and expense. Tenant must deliver Tenant's Review Notice to Landlord within
thirty (30) days after Tenant has received its reconciliation statement for the
prior year and must complete its review within forty-five (45) days after
receipt of such statement. Failure by Tenant to deliver Tenant's Review Notice
to Landlord within such thirty (30) day period or to perform its review within
such forty-five (45) day period shall constitute a waiver of Tenant's rights to
contest such statements. Tenant shall pay the full amount of Tenant's Operating
Costs Payment shown to be due on the statement without delay, but by doing so
shall not waive its rights to review Landlord's books and records or to dispute
the accuracy or appropriateness of any such statement or any items thereon as
provided in this Section 5.1B. If such review discloses a discrepancy in
Landlord's calculation of Tenant's Operating Cost Payment, Landlord shall
promptly pay to Tenant the amount of any overpayment by Tenant or Tenant shall
promptly pay to Landlord the amount of any underpayment by Tenant, as the case
may be. Tenant and Tenant's agents hereby agree that all information disclosed
in the books and records shall be kept confidential and shall not be disclosed
to any other party, including, but not limited to, any other tenant in the
Building. Tenant further agrees to cause any third party engaged by Tenant to
review said books and records to execute and deliver a confidentiality agreement
in a form reasonably acceptable to Landlord prior to its performing any such
review. In addition, any accountants or other professional retained by Tenant to
review Landlord's statement pursuant to this Section 5.1B shall be subject to
Landlord's approval, not to be unreasonably withheld, and shall be paid by
Tenant on a fixed hourly basis, and not on a contingency fee based upon a
percentage of the recovery of any

                                                                              10
<PAGE>

discrepancy discovered in Landlord's statement.

            C. If the Term ends on a date other than the last day of December,
the actual Operating Costs for the year in which the Expiration Date occurs,
shall be prorated so that Tenant shall pay that portion of Tenant's Operating
Costs Payment for such year represented by a fraction, the numerator of which
shall be the number of days during such fractional year falling within the Term,
and the denominator of which is 365 (or 366, in the case of a leap year). The
provisions of this Section 5.1 shall survive the Expiration Date or any sooner
termination provided for in this Lease.

      Section 5.2 A. For purposes of this Lease, the term "Operating Costs"
shall mean any and all expenses, costs and disbursements of every kind which
Landlord pays, incurs or becomes obligated to pay in connection with the
operation, management, repair and maintenance of all or any portion of the
Premises. All Operating Costs shall be determined according to generally
accepted accounting principles which shall be consistently applied. Operating
Costs include, without limitation, the following: (a) Commercially reasonable
wages, salaries, benefits and fees of all personnel or entities engaged in the
operation, repair, maintenance, management, or safekeeping of the Premises,
including taxes, insurance, and benefits relating thereto and the costs of all
supplies and materials (including work clothes and uniforms) used in the
operation, repair, maintenance and security of the Premises; (b) The reasonable
costs of performance by Landlord's personnel of, or of all service agreements
for, maintenance, janitorial services, access control, alarm service, window
cleaning, elevator maintenance and landscaping for the Premises. Such cost shall
include the rental of personal property and equipment used by Landlord's
personnel and others in the maintenance and repair of the Premises; (c) Cost of
utilities for the Premises, including water, sewer, gas, fuel and Common Area
power, electricity, lighting and air conditioning, heating and ventilating; (d)
Cost of all insurance, including casualty and liability insurance applicable to
the Premises and to Landlord's equipment, fixtures and personal property used in
connection therewith, business interruption or rent insurance against such
perils as are commonly insured against by prudent landlords, such other
insurance as may reasonably be required by any lessor or mortgagee of Landlord,
and such other insurance which Landlord considers reasonably necessary in the
operation of the Premises, together with all appraisal and consultants' fees in
connection with such insurance; (e) All Taxes. For purposes hereof, the term
"Taxes" shall mean, all taxes, assessments, and other governmental charges,
applicable to or assessed against the Premises or any portion thereof, or
applicable to or assessed against Landlord's personal property used in
connection therewith, whether federal, state, county, or municipal and whether
assessed by taxing districts or authorities presently taxing the Premises or the
operation thereof or by other taxing authorities subsequently created, or
otherwise, and any other taxes and assessments attributable to or assessed
against all or any part of the Premises or its operation; including any
reasonable expenses, including fees and disbursements of attorneys, tax
consultants, arbitrators, appraisers, experts and other witnesses, incurred by
Landlord in contesting any taxes or the assessed valuation of all or any part of
the Premises. Tenant acknowledges that Taxes "for" a given calendar year are
those Taxes paid for the Premises in such calendar year even if assessed for
periods of time other than the given year. If at any time during the Term there
shall be levied, assessed, or imposed on Landlord or all or any part of the
Premises by any governmental entity any general or special ad valorem or other
charge or tax directly upon rents received under leases, or if any fee, tax,
assessment, or other charge is imposed which is measured by

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<PAGE>

or based, in whole or in part, upon such rents, or if any charge or tax is made
based directly or indirectly upon the transactions represented by leases or the
occupancy or use of the Premises or any portion thereof, such taxes, fees,
assessments or other charges shall be deemed to be Taxes. Notwithstanding the
foregoing, any (A) franchise, corporation, income or net profits tax, unless
substituted for real estate taxes or imposed as additional charges in connection
with the ownership of the Premises, which may be assessed against Landlord or
the Premises or both, (B) transfer taxes assessed against Landlord or the
Premises or both, and (C) penalties or interest on any late payments of Landlord
shall be excluded from Taxes. If any or all of the Taxes paid hereunder are by
law permitted to be paid in installments, notwithstanding how Landlord pays the
same, then, for purposes of calculating Operating Costs, such Taxes shall be
deemed to have been divided and paid in the maximum number of installments
permitted by law, and there shall be included in Operating Costs for each year
only such installments as are required by law to be paid within such year,
together with interest thereon and on future such installments as provided by
law; (f) Legal and accounting costs reasonably incurred by Landlord or paid by
Landlord to third parties (exclusive of legal fees or accounting costs with
respect to the ownership rather than the operation of the Premises), appraisal
fees, (consulting fees), for operation of the Premises; (g) Cost of repairs and
maintenance for the Premises (excluding repairs and maintenance paid by proceeds
of insurance or by Tenant); (h) the cost of improvements or equipment which (i)
are for the purpose of reducing Operating Costs for the Premises, each year, up
to the amount saved in such year, as a result of the installation thereof, as
reasonably estimated by Landlord, or (ii) enhance the Premises for the general
benefit of tenants or occupants thereof (in manner similar to other first class
office building in the Chicago suburban area), or (iii) are required by any
governmental authority (excluding, if not caused by Tenant or to employees,
agents, representatives, contractors, licensees or invitees, all environment
costs such as costs of investigation or remediation); and (iv) a management fee
(whether or not Landlord engages a manager for the Premises or manages the
Premises with Landlord's personnel) and all items reimbursable to the Premises
manager, if any, pursuant to any management contract for the Premises. The
management fee shall be three percent (3%) of the gross receipts from the
operation of the Premises. Landlord covenants and agrees that all Operating
Costs shall be commercially reasonable in nature and shall be substantially the
same as the Operating Costs associated with first-class office buildings in the
Chicago suburban area.

            B. "Operating Costs" shall not include (a) expenses for which
Landlord is reimbursed or indemnified (either by an insurer, condemner,
warrantor or otherwise) to the extent of funds received by Landlord; (b)
interest or amortization payments on any mortgages; (c) net basic rents under
ground leases; or (d) costs representing an amount paid to an affiliate of
Landlord which is in excess of the amount which would have been paid in the
absence of such relationship.

            C. Notwithstanding the foregoing, capital improvements to the
Premises which are Operating Costs shall be amortized on a straight line basis,
over the useful life thereof using an interest rate of ten and one half percent
(10.5%) per annum, and Tenant shall pay on a monthly basis the portion of such
useful life which falls within each month of the Term (as the same may be
extended). The useful life of a capital improvement shall be subject to
adjustment as a result of Tenant's use pattern of the capital improvement which
is other than ordinary and customary use of an item.

                                                                              12
<PAGE>
                                    ARTICLE 6

                         REPRESENTATIONS AND WARRANTIES

      6.1 Landlord hereby represents and warrants that other than as set forth
on Schedule 6.1, (a) it has no actual knowledge of material defects in the
Central systems or structural components of the Building; (b) it knows of no
material repairs or capital improvements which will be required to be made on or
before the second anniversary of the Lease; (c) it has the full power, right and
authority to execute this Lease and the execution of the Lease shall not
conflict with any other agreement or obligation of Landlord; (d) it is a limited
partnership duly organized, validly existing and in good standing under the laws
of Delaware with all requisite power and authority to lease the Premises and
carry on its business as currently conducted; and (e) Landlord has no actual
knowledge of any Hazardous Materials at, on or under the Premises in violation
of law.
..
      6.2 Tenant hereby represents and warrants that (a) it is a corporation
duly organized , validly existing and in good standing under the laws of
Delaware with all requisite power and authority to lease the Premises and carry
on its business as currently conducted; and (b) it has the full power, right and
authority to execute this Lease and the execution of the Lease does not conflict
with any other agreement or obligation of Tenant.

                                    ARTICLE 7

                              SERVICES OF LANDLORD

      Section 7.1 A. During the Term, Landlord shall furnish Tenant with the
following services at such hours as Tenant requires: (a) hot and cold water in
Building Standard bathrooms and chilled water in Building Standard drinking
fountains; (b) permit Tenant to use Central systems, such as then existing
feeders and risers, to obtain electrical power from the utility supplier
sufficient for lighting the Premises and for the operation therein of
typewriters, voicewriters, calculating machines, word processing equipment,
photographic reproduction equipment, copying machines, personal computers and
similar items of business equipment which consume, in the aggregate, less than
five (5) watts per square foot of Rentable Area of the Premises and require a
voltage of 120 volt single phase or less; (c) heating, ventilating or
air-conditioning, as appropriate, to the Premises, at such temperatures and in
such amounts as customarily and seasonally provided to tenants occupying
comparable space in first-class office buildings in the Chicago suburban area;
(d) electric lighting for the exterior areas of the Premises; (e) passenger
elevator service for access to and from the Premises twenty-four (24) hours per
day, seven (7) day per week; (f) janitorial cleaning services; (g) facilities
for Tenant's loading, unloading, delivery and pick-up activities, including
access thereto, subject to the Rules and Regulations, the type of facilities,
and other limitations of such loading facilities; and (h) replacement, as
necessary, of all Building Standard lamps and ballasts in Building Standard
light fixtures within the Premises, with Tenant to pay for all bulbs and
ballasts and to purchase such bulbs and ballasts solely from Landlord. All
services referred to in this Section 7.1 shall be provided by Landlord and paid
for by Tenant as part of Tenant's Operating Costs Payment. At no time shall use
of electricity in the Premises exceed the capacity of existing feeders and
risers to or wiring in the

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<PAGE>

Premises. Any risers or wiring to meet Tenant's excess electrical requirements
shall, upon Tenant's written request, be installed by Landlord, at Tenant's sole
cost, if, in Landlord's reasonable judgment, the same are necessary and shall
not (i) cause permanent damage or injury to the Building or the Premises, (ii)
cause or create a dangerous or hazardous condition, (iii) entail excessive or
unreasonable alterations, repairs or expenses.

            B. If any machinery or equipment which generates abnormal heat or
otherwise creates unusual demands on the air conditioning or heating system
serving the Premises is used in the Premises and if Tenant has not, within five
(5) days after demand from Landlord, taken such steps, at Tenant's expense, as
shall be necessary to cease such adverse affect on the air conditioning or
heating system, Landlord shall have the right to install supplemental air
conditioning or heating units in the Premises, and the full cost of such
supplemental units (including the cost of acquisition, installation, operation,
use and maintenance thereof) shall be paid by Tenant to Landlord in advance or
on demand as Additional Rent.

      Section 7.2 During the Term, Tenant agrees to allow Landlord to act as
agent on behalf of Tenant with the Electricity Supplier, as defined below;
provided that Landlord may not charge Tenant any fee (other than the management
fee provided for in Article 5) or mark-up which would make Tenant's cost more
than the costs of electricity Tenant would have paid had Tenant secured
electricity itself. As agent, Landlord will supply or contract for the supply of
such electrical services to the Premises such that Tenant shall receive
electrical power sufficient for lighting the Premises and for the operation
therein of typewriters, voicewriters, calculating machines, word processing
equipment, photographic reproduction equipment, copying machines, personal
computers and similar items of business equipment which consume, in the
aggregate, less than five (5) watts per square foot of rentable area of the
Premises and require a voltage of 120 volt single phase or less.

            Additionally, during the Term, Tenant agrees to allow Landlord to
act as agent on behalf of Tenant with the Suppliers, as defined below. As agent,
Landlord will supply or contract for the supply of all of the utilities supplied
by the Suppliers, provided, however, if Landlord elects not to act as agent on
behalf of Tenant with the Suppliers, Landlord shall notify Tenant of same and
Tenant shall then make all necessary arrangements with the public utility or
alternative utility service suppliers ("Suppliers") approved by Landlord
supplying electric, gas, telephone, cable or other utility services to furnish
such utility services to the Premises, and shall be subject to the rules and
regulations of the Suppliers of such services and the rules and regulations of
any municipal or other governmental authority regulating the business of
providing such services. In such case, Tenant shall be responsible for
contracting promptly and directly with such Suppliers and for paying all
deposits for, and all costs relating to, such services, so that services are
available to the Premises for Tenant's use. Tenant shall cooperate with
Landlord, the Suppliers and the service supplier supplying electricity directly
to the Premises (the "Electricity Supplier"), at all times and, as reasonably
necessary, shall allow Landlord, the Suppliers and the Electricity Supplier,
reasonable access to the Building's lines, feeders, risers, wiring, pipes,
meters and any other machinery within the Building or at the Premises.
Notwithstanding the foregoing, Landlord shall not have the right to bind Tenant
to any agreement with such suppliers without Tenant's written consent.

      Section 7.3 Notwithstanding anything contained in the Lease to the
contrary, Landlord

                                                                              14
<PAGE>

shall in no way be liable or responsible for any loss, damage, or expense that
Tenant may sustain or incur by reason of any change, failure, interference,
disruption, or defect in the supply or character of the utility services
furnished to the Premises, or if the quantity or character of the utility
services supplied by the Suppliers is no longer available or suitable for
Tenant's requirements, and no such change, failure, defect, unavailability, or
unsuitability shall constitute an actual or constructive eviction, in whole or
in part, will entitle Tenant to any abatement or diminution of Rent or relieve
Tenant from any of its obligations under this Lease. Should any malfunction of
any systems or facilities occur within the Building or should maintenance or
alterations of such systems or facilities become necessary, Landlord shall
repair the same promptly and with reasonable diligence, and Tenant shall have no
claim for rebate, abatement of Rent or damages because of malfunctions or any
such interruptions in service, except for any such malfunction caused by or
maintenance or alteration required as a result of Landlord or its agents or
representative's gross negligence or willful misconduct. Notwithstanding the
foregoing, in the event there is failure, delay or interruption of utility
services, any maintenance or alteration which in any such case is due to
Landlord's gross negligence or willful misconduct and causes the Premises (or
any portion thereof) to be untenantable or prohibits access to the Premises, and
as a result of either occurrence, Tenant in fact ceases to use the Premises (or
any portion thereof) for a period in excess of five (5) consecutive Business
Days, then commencing on the sixth (6th) consecutive Business Day of such
untenantability and non-use, Rent payable by Tenant for the untenantable portion
of the Premises shall be abated until the earliest to occur of (a) the date such
failure, delay or interruption is remedied, (b) the date the Premises are again
tenantable or (c) the date Tenant resumes use of the Premises. For the purposes
of this Section 7.3, the Premises (or any portion thereof) shall be deemed
"untenantable" if Tenant cannot and is not conducting business due to such
failure, delay or interruption of utility services in the Premises (or any
portion thereof).

                                    ARTICLE 8

                            ASSIGNMENT AND SUBLETTING

      Section 8.1 Neither Tenant nor its legal representatives or successors in
interest shall, by operation of law or otherwise, assign, mortgage, pledge,
encumber or otherwise transfer this Lease or any part hereof, or the interest of
Tenant under this Lease, or in any sublease or the rent thereunder. The Premises
or any part thereof shall not be sublet, occupied or used for any purpose by
anyone other than Tenant, without Tenant's obtaining in each instance the prior
written consent of Landlord in the manner hereinafter provided. Tenant shall not
modify, extend, or amend a sublease previously consented to by Landlord without
obtaining Landlord's prior written consent thereto.

      Section 8.2 An assignment of this Lease shall be deemed to have occurred
(a) if in a single transaction or in a series of transactions more than 50% in
interest in Tenant, any guarantor of this Lease, or any subtenant (whether
stock, partnership, interest or otherwise) is transferred, diluted, reduced, or
otherwise affected with the result that the present holder or owners of Tenant,
such guarantor, or such subtenant have less than a 50% interest in Tenant, such
guarantor or such subtenant, or (b) if Tenant's obligations under this Lease are
taken over or assumed in consideration of Tenant leasing space in another office
building. The transfer of the outstanding capital stock of any corporate Tenant,
guarantor or subtenant through the "over-the-counter" market or any

                                                                              15
<PAGE>

recognized national securities exchange (other than by persons owning 5% or more
of the voting calculation of such 50% interest of clause 8.2(a) above) shall not
be included in the calculation of such 50% interest in clause (a) above.

      Section 8.3 Notwithstanding anything to the contrary in Section 8.1,
Tenant shall have the right, upon ten (10) days' prior written notice to
Landlord, to (a) sublet all or part of the Premises to any related corporation
or other entity which controls Tenant, is controlled by Tenant or is under
common control with Tenant; or (b) assign this Lease to a successor corporation
or other entity into which or with which Tenant is merged or consolidated or
which acquired substantially all of Tenant's assets and property; provided that
(i) such successor corporation assumes substantially all of the obligations and
liabilities of Tenant and shall have a net worth at least equal to the net worth
of Tenant as of the date of this Lease as determined by generally accepted
accounting principles, and (ii) Tenant shall provide in its notice to Landlord
the information required in Section 8.4. For the purpose hereof "control" shall
mean ownership of not less than 50% of all the voting stock or legal and
equitable interest in such corporation or entity.

      Section 8.4 If Tenant should desire to assign this Lease or sublet the
Premises (or any part thereof), Tenant shall give Landlord written notice no
later than the time required for notice under Section 8.3 in the case of an
assignment or subletting to a related or successor entity as more fully provided
under Section 8.3, or sixty (60) days in advance of the proposed effective date
of any other proposed assignment or sublease, specifying (a) the name, current
address, and business of the proposed assignee or sublessee, (b) the amount and
location of the space within the Premises proposed to be so subleased, (c) the
proposed effective date and duration of the assignment or subletting, and (d)
the proposed rent or consideration to be paid to Tenant by such assignee or
sublessee. Tenant shall promptly supply Landlord with financial statements and
other information as Landlord may request to evaluate the proposed assignment or
sublease. For assignments and sublettings other than those permitted by Section
8.3, Landlord shall have fifteen (15) Business Days following receipt of such
notice and other information requested by Landlord within which to notify Tenant
in writing that Landlord elects: (i) to terminate this Lease as to the space so
affected as of the proposed effective date set forth in Tenant's notice, in
which event Tenant shall be relieved of all further obligations hereunder as to
such space, except for obligations under Articles 17 and 22 and all other
provisions of this Lease which expressly survive the termination hereof; or (ii)
to permit Tenant to assign or sublet such space; provided, however, that, if the
rent rate agreed upon between Tenant and its proposed subtenant is greater than
the rent rate that Tenant must pay Landlord hereunder for that portion of the
Premises, or if any consideration shall be promised to or received by Tenant in
connection with such proposed assignment or sublease (in addition to rent), then
fifty percent (50%) of such excess rent and other consideration shall be
considered Additional Rent owed by Tenant to Landlord (less brokerage
commissions, attorneys' fees and other disbursements reasonably incurred by
Tenant for such assignment and subletting if acceptable evidence of such
disbursements is delivered to Landlord), and shall be paid by Tenant to
Landlord, in the case of excess rent, in the same manner that Tenant pays Base
Rent and, in the case of any other consideration, within ten (10) Business Days
after receipt thereof by Tenant; or (iii) to refuse, in Landlord's reasonable
discretion, to consent to Tenant's assignment or subleasing of such space and to
continue this Lease in full force and effect as to the entire Premises. The
parties agree that Landlord may reasonably refuse to consent to an assignment or
subletting if the proposed assignee or

                                                                              16
<PAGE>

subtenant is not financially creditworthy, is a governmental authority or
agency, an organization or person enjoying sovereign or diplomatic immunity, a
medical or dental practice or a user that will attract a volume, frequency or
type of visitor or employee to the Building which is not consistent with the
standards of a high quality office building or that will impose an excessive
demand on or use of the facilities or services of the Building; provided,
however, that the foregoing are merely examples of reasons for which Landlord
may withhold its approval and shall not be deemed exclusive of any permitted
reasons for reasonably withholding approval, whether similar or dissimilar to
the foregoing examples. It shall also be reasonable for Landlord to refuse to
consent to any assignment or subletting if (i) Tenant is then in default under
this Lease, or (ii) such assignment of subletting would cause a default under
any ground lease, deed of trust, mortgage, restrictive covenant, easement or
other encumbrance affecting the Premises. Whether or not Landlord approves of a
proposed assignment or sublet, Tenant agrees to reimburse Landlord as Additional
Rent for reasonable and customary legal fees, a reasonable administrative fee
and any other reasonable costs incurred by Landlord in connection with any
proposed assignment or subletting and such payment shall not be deducted from
the Additional Rent, if any, owed to Landlord pursuant to subsection (ii) above.
Tenant shall deliver to Landlord copies of all documents executed in connection
with any permitted assignment or subletting, which documents shall be in form
and substance reasonably satisfactory to Landlord and which shall require any
assignee to assume performance of all terms of this Lease to be performed by
Tenant or any subtenant to comply with all the terms of this Lease to be
performed by Tenant. No acceptance by Landlord of any Rent or any other sum of
money from any assignee, sublessee or other category of transferee shall be
deemed to constitute Landlord's consent to any assignment, sublease, or
transfer.

      Unless otherwise agreed to in writing by Landlord, no such assignment or
sublease shall release Tenant from any of its obligations under this Lease.

      Section 8.5 Any attempted assignment or sublease by Tenant in violation of
the terms and provisions of this Article 8 shall be void and shall constitute a
material breach of this Lease. In no event, shall any assignment, subletting or
transfer, whether or not with Landlord's consent, relieve Tenant of its primary
liability under this Lease for the entire Term, and Tenant shall in no way be
released from the full and complete performance of all the terms hereof. If
Landlord takes possession of the Premises before the expiration of the Term of
this Lease, Landlord shall have the right, at its option, to terminate all
subleases, unless otherwise agreed in writing by Landlord, or to take over any
sublease of the Premises or any portion thereof and such subtenant shall attorn
to Landlord, as its landlord, under all the terms and obligations of such
sublease occurring from and after such date, but excluding previous acts,
omissions, negligence or defaults of Tenant and any repair or obligation in
excess of available net insurance proceeds or condemnation award.

      Section 8.6 A. Tenant acknowledges that this Lease is a lease of
nonresidential real property and therefore agrees that Tenant, as the debtor in
possession, or the trustee for Tenant (collectively the "Trustee") in any
proceeding under Title 11 of the United State Bankruptcy Code relating to
Bankruptcy, as amended (the "Bankruptcy Code"), shall not seek or request any
extension of time to assume or reject this Lease or to perform any obligations
of this Lease which arise from or after the order of relief.

                                                                              17
<PAGE>

      B. The Trustee shall have the right to assume or assign Tenant's rights
and obligations under this Lease only if the Trustee: (a) promptly cures or
provides adequate assurance that the Trustee will promptly cure any default
under the Lease; (b) compensates or provides adequate assurance that the Trustee
will promptly compensate Landlord for any actual pecuniary loss incurred by
Landlord as a result of Tenant's default under this Lease; and (c) provides
adequate assurance of future performance under the Lease. All payments of Rent
required of Tenant under this Lease, whether or not expressly denominated as
such in this Lease, shall constitute rent for the purposes of Title 11 of the
Bankruptcy Code.

      Section 8.7 The term "Landlord," as used in this Lease, so far as
covenants or obligations on the part of Landlord are concerned, shall be limited
to mean and include only the owner or owners, at the time in question, of the
fee title to, or a lessee's interest in a ground lease of, the Land or the
Building. In the event of any transfer, assignment or other conveyance or
transfers of any such title or interest, Landlord herein named (and in case of
any subsequent transfers or conveyances of any such title or interest, the then
grantor) shall be automatically freed and relieved from and after the date of
such transfer, assignment or conveyance of all liability as respects the
performance of any covenants or obligations on the part of Landlord contained in
this Lease thereafter to be performed and, without further agreement, the
transferee of such title or interest shall be deemed to have assumed and agreed
to observe and perform any and all obligations of Landlord hereunder, during its
ownership of the Premises. Landlord may transfer its interest in the Premises,
or portions thereof on interest therein, without the consent of Tenant and such
transfer or subsequent transfer shall not be deemed a violation on Landlord's
part of any of the terms of this Lease.

                                    ARTICLE 9

                                     REPAIRS

      Section 9.1 Except for ordinary wear and tear, and except as otherwise
provided in Section 9.2, Landlord shall perform all maintenance and make all
repairs and replacements to the Premises and shall do so in good and workman
like manner. In no event shall Landlord have any obligation to maintain, repair
or replace any furniture, furnishings, fixtures or personal property of Tenant.

      Section 9.2 Tenant shall keep the Premises in good order and in a safe,
neat and clean condition. No representations respecting the condition of the
Premises or the Building or the other portions of the Premises have been made by
Landlord to Tenant except as specifically set forth in this Lease. Except as
provided in Section 10.1 or specifically consented to by Landlord, Tenant shall
not perform any maintenance or repair work or make any replacement in or to the
Premises but rather shall promptly notify Landlord of the need for such
maintenance, repair or replacement so that Landlord may proceed to perform the
same pursuant to the provisions of Section 9.1. In the event Landlord
specifically consents to the performance of any maintenance or the making of any
repairs or replacements by Tenant and Tenant fails to promptly commence and
diligently pursue the performance of such maintenance or the making of such
repairs or replacements, then Landlord, at its option, may perform such
maintenance or make such repairs and Tenant shall pay as Additional Rent

                                                                              18
<PAGE>

to Landlord, on demand after Tenant receives an invoice therefor, the cost
thereof plus a fee equal to ten percent (10%) of the actual costs to cover
overhead and a fee for Landlord's agent or manager.

      Section 9.3 All repairs made by Tenant pursuant to Section 9.2 shall be
performed in a good and workmanlike manner and in accordance with Section 10.2
by licensed contractors or other licensed repair personnel, approved by
Landlord, which approval shall not be unreasonably withheld or delayed;
provided, however, that neither Tenant nor its contractors or repair personnel
shall be permitted to do any work affecting the Central systems of the Building.
In no event shall such work be done for Landlord's account or in a manner which
allows any liens to be filed in violation of Article 11. To the extent any
repairs involve the making of alterations to the Premises, Tenant shall comply
with the provisions of Article 10.

                                   ARTICLE 10

                                   ALTERATIONS

      Section 10.1 Tenant shall not at any time during the Term make any
alterations to the Premises without first obtaining Landlord's written consent
thereto, which consent Landlord shall not unreasonably withhold or delay;
provided, however, that Landlord shall not be deemed unreasonable by refusing to
consent to any alterations which are visible from the exterior of the Building
or the Premises, which will or are likely to cause any weakening of any part of
the structure of the Premises or the Building which will or are likely to cause
damage or disruption to the Central Building systems or which are prohibited by
any underlying ground lease or mortgage. Should Tenant desire to make any
alterations to the Premises, Tenant shall submit all plans and specifications
for such proposed alterations to Landlord for Landlord's review before Tenant
allows any such work to commence, and Landlord shall promptly approve or
disapprove such plans and specifications for any of the reasons set forth in
this Section 10.1 or for any other reason reasonably deemed sufficient by
Landlord. Tenant shall select and use only licensed contractors, subcontractors
or other repair personnel approved by Landlord, which approval shall not be
unreasonably withheld or delayed. Upon Tenant's receipt of written approval from
Landlord and any required approval of any mortgagee or lessor of Landlord, and
upon Tenant's payment to Landlord of (a) a reasonable fee, not to exceed
$2,500.00 (which amount shall increase by three percent (3%) each anniversary of
the Commencement Date) for the work of Landlord and Landlord's employees in
reviewing and approving such plans and specifications plus the reasonable
out-of-pocket costs incurred by Landlord on consultants reviewing such plans and
specifications; and (b) the fees, if any charged by any mortgagee or lessor of
Landlord for such review and approval, Tenant shall have the right to proceed
with the construction of all approved alterations, but only so long as such
alterations are in strict compliance with the plans and specifications so
approved by Landlord and with the provisions of this Article 10. All alterations
shall be made at Tenant's sole cost and expense, either by Tenant's contractors
or, at Tenant's option, by Landlord on terms reasonably satisfactory to Tenant,
including a fee of ten percent (10%) of the actual costs of such work to cover
Landlord's overhead and a fee for Landlord's agent or manager in supervising and
coordinating such work. If Tenant's contractor performs such work, there shall
be a fee of five percent (5%) of the actual costs of such work for Landlord's
agent or manager in supervising and coordinating such work and to cover
overhead. Tenant shall not be required to pay Landlord the fees of Landlord
specified in this Section 10.1 with

                                                                              19
<PAGE>

respect to any alterations made prior to the second anniversary of the
Commencement Date. In no event shall anyone other than Landlord or Landlord's
employees or representatives perform work to be done which affects the Central
systems of the Building. Specific consent from Landlord shall not be required
for work costing less than fifty thousand and 00/100 dollars ($50,000.00) for
each project (and one hundred thousand and 00/100 dollars ($100,000.00) in the
aggregate for any twelve (12) month period) so long as such work (i) does not
involve Hazardous Materials, (ii) does not affect central systems or the
structure of the Building or constitute base building modifications, and (iii)
is not visible from outside the Premises and would not materially detract from
the aesthetic integrity of the Building or its design. Tenant may perform such
work so long as Tenant informs Landlord in reasonable detail of the nature of
the work and otherwise complies with the provisions of this Article 10.

      Section 10.2 All construction, alterations and repair work done by or for
Tenant pursuant to any provision of this Lease shall (a) be performed in such a
manner as to maintain harmonious labor relations; (b) not adversely affect the
safety of the Building or the Premises or the systems thereof and not affect the
Central systems of the Building; (c) comply with all building, safety, fire,
plumbing, electrical, and other codes and governmental and insurance
requirements; (d) not result in any usage in excess of building standard water,
electricity, gas, or other utilities or of heating, ventilating or
air-conditioning (either during or after such work) unless prior written
arrangements satisfactory to Landlord are made with respect thereto; and (e) be
completed promptly and in a good and workmanlike manner. After completion of any
alterations to the Premises, Tenant will deliver to Landlord a copy of "as
built" plans and specifications depicting and describing such alterations.

      Section 10.3 All leasehold improvements, alterations and other physical
additions made to or installed by or for Tenant in the Premises after the
Commencement Date of the Lease, shall be and remain Landlord's property (except
for Tenant's furniture, personal property and movable trade fixtures) and shall
not be removed without Landlord's written consent. Tenant agrees to remove, at
its sole cost and expense, all of Tenant's furniture, personal property and
movable trade fixtures, and, if directed to or permitted to do so by Landlord in
writing, all, or any part of, the leasehold improvements, alterations and other
physical additions made by Tenant to the Premises, before the Expiration Date or
any earlier date of termination of this Lease; provided, however, that if in
response to a written request by Tenant at the time it makes any improvement,
alteration or other physical addition that Tenant be permitted to leave such
improvement, alteration or other physical addition at the Premises upon the
Expiration Date or earlier termination of this Lease, Landlord does not require
in writing that Tenant remove such improvement, alteration or other physical
addition, Tenant shall not be required to remove such improvement, alteration or
other physical addition. Tenant shall repair, or promptly reimburse Landlord for
the cost of repairing, all damage done to the Premises or the Building by such
removal. Any leasehold improvements, alterations or physical additions made by
Tenant which Landlord does not direct or permit Tenant to remove at any time
during or at the end of the Term shall become the property of Landlord at the
end of the Term without any payment to Tenant. If Tenant fails to remove any of
Tenant's furniture, personal property or movable trade fixtures by the
Expiration Date or any sooner date of termination of the Lease or, if Tenant
fails to remove any leasehold improvements, alterations and other physical
additions made by Tenant to the Premises which Landlord has in writing directed
Tenant to remove, Landlord shall have the right, on the fifth (5th) day after
Landlord's delivery of written notice to

                                                                              20
<PAGE>

Tenant to deem such property abandoned by Tenant and to remove, store, sell,
discard or otherwise deal with or dispose of such abandoned property in a
commercially reasonable manner. Tenant shall be liable for all costs of such
disposition of Tenant's abandoned property, and Landlord shall have no liability
to Tenant in any respect regarding such property of Tenant. The provisions of
this Section 10.3 shall survive the expiration or any earlier termination of
this Lease.

      Section 10.4 Provided no Event of Default by Tenant exists, as an
allowance for alterations Tenant wishes to make to the Premises, Landlord agrees
to pay to Tenant $1,013,594.40 at any time after the Commencement Date during
calendar year 2000 and $434,397.60 at any time during calendar year 2001. Such
amounts shall be paid by Landlord within thirty (30) days after Landlord's
receipt of written request therefor.

                                   ARTICLE 11

                                      LIENS

      Section 11.1 Tenant shall keep the Building and the Premises and
Landlord's interest therein free from any liens arising from any work performed,
materials furnished, or obligations incurred by, or on behalf of Tenant (other
than by Landlord). Notice is hereby given that neither Landlord nor any
mortgagee or lessor of Landlord shall be liable for any labor or materials
furnished to Tenant. If any lien is filed for such work or materials, such lien
shall encumber only Tenant's interest in leasehold improvements on the Premises.
Within ten (10) Business Days after Tenant learns of the filing of any such
lien, Tenant shall notify Landlord of such lien and shall either discharge and
cancel such lien of record or post a bond sufficient under the laws of the State
of Illinois to cover the amount of the lien claim plus any penalties, interest,
attorneys' fees, court costs, and other legal expenses in connection with such
lien. If Tenant fails to so discharge or bond such lien within ten (10) calendar
days after written demand from Landlord, Landlord shall have the right, at
Landlord's option, to pay the full amount of such lien without inquiry into the
validity thereof, and Landlord shall be promptly reimbursed by Tenant, as
Additional Rent, for all amounts so paid by Landlord, including expenses,
interest, and attorneys' fees.

                                   ARTICLE 12

                          USE AND COMPLIANCE WITH LAWS

      Section 12.1 The Premises shall be used only for executive and
administrative offices for the conduct of Tenant's business and such ancillary
services normally connected therewith (such as employee cafeteria services) and
for no other purposes whatsoever. Tenant shall use and maintain the Premises in
a clean, careful, safe, lawful and proper manner and shall not allow within the
Premises, any offensive noise, odor, conduct or private or public nuisance or
permit Tenant's employees, agents, licensees or invitees to create a public or
private nuisance or act in a disorderly manner within the Building or in the
Premises.

      Section 12.2 Subject to Landlord's obligations under Article 9 of this
Lease, Tenant shall, at Tenant's sole expense, (a) comply with all laws, orders,
ordinances, and regulations of federal, state,

                                                                              21
<PAGE>

county, and municipal authorities having jurisdiction over the Premises, (b)
comply with any directive, order or citation made pursuant to law by any public
officer requiring abatement of any nuisance caused by Tenant or its agents,
employees, invitees, licensees or contractors or which imposes upon Landlord or
Tenant any duty or obligation arising from Tenant's occupancy or use of the
Premises or from conditions which have been created by or at the request or
insistence of Tenant, or required by reason of a breach of any of Tenant's
obligations hereunder or by or through other fault of Tenant, (c) comply with
all insurance requirements applicable to the Premises and (d) indemnify and hold
Landlord harmless from any loss, cost, claim or expense which Landlord incurs or
suffers by reason of Tenant's failure to comply with its obligations under
clauses (a), (b) or (c) above. If Tenant receives notice of any such directive,
order citation or of any violation of any law, order, ordinance, regulation or
any insurance requirement, Tenant shall promptly notify Landlord in writing of
such alleged violation and furnish Landlord with a copy of such notice.

      Section 12.3 Tenant shall not, nor shall Tenant permit any third party, to
use, store, generate, treat, release or dispose at, on or under the Premises,
any "Hazardous Substance" (as hereinafter defined), except for Hazardous
Substances which are a part of or contained in customary office supplies and/or
equipment and then only if used, stored, and disposed of in accordance with
manufacturer's instructions and all applicable laws, codes, regulations, orders
and ordinances, and any such action shall constitute a default under this Lease.
Tenant shall indemnify, defend and hold Landlord, any managing agents and
leasing agents of the Building, and their respective agents, partners, officers,
directors and employees, harmless from all damages, costs, losses, expenses
(including, but not limited to, attorneys' fees, consulting fees and engineers'
fees) arising from or attributable to any breach by Tenant of the covenants
contained in this Section 12.3. Tenant's indemnification obligations hereunder
shall survive the termination or expiration of this Lease. As used herein, the
term "Hazardous Substance" shall mean any substance, material, waste, gas or
particulate matter which is regulated by any local governmental authority, the
State of Illinois, or the United States Government, including, but not limited
to (i) any material or substance which is defined or designated as a "hazardous
waste," "hazardous material," "hazardous substance," "extremely hazardous
waste," or "restricted hazardous waste" under any provision of Illinois or
federal law; (ii) oil or petroleum; (iii) asbestos and asbestos-containing
materials; (iv) polychlorinated biphenyls; and (v) radioactive material.

                                                                              22
<PAGE>

                                   ARTICLE 13

                              DEFAULT AND REMEDIES

      Section 13.1 The occurrence of any one or more of the following events
shall constitute an Event of Default (herein so called) of Tenant under this
Lease: (a) if Tenant fails to pay any Rent hereunder as and when such Rent
becomes due and such failure shall continue for more than five (5) days after
Landlord gives Tenant notice of past due Rent; (b) if Tenant fails to pay Rent
on time more than twice in any period of twelve (12) months, notwithstanding
that such payments have been made within the applicable cure period; (c) if the
Premises become vacant, deserted, or abandoned for more than ten (10)
consecutive Business Days or if Tenant fails to take possession of the Premises
on the Commencement Date or promptly thereafter; (d) if Tenant permits to be
done anything which creates a lien upon the Premises and fails to discharge or
bond such lien or post such security with Landlord as is required by Article 11;
(e) if Tenant violates the provisions of Article 8 by attempting to make an
unpermitted assignment or sublease; (f) if Tenant fails to maintain in force all
policies of insurance required by this Lease and such failure shall continue for
more than ten (10) Business Days after Landlord gives Tenant notice of such
failure; (g) if any petition is filed by or against Tenant or any guarantor of
this Lease under any present or future section or chapter of the Bankruptcy
Code, or under any similar law or statute of the United States or any state
thereof (which, in the case of an involuntary proceeding, is not permanently
discharged, dismissed, stayed, or vacated, as the case may be, within sixty (60)
days of commencement), or if any order for relief shall be entered against
Tenant or any guarantor of this Lease in any such proceedings; (h) if Tenant or
any guarantor of this Lease becomes insolvent or makes a transfer in fraud of
creditors or makes an assignment for the benefit of creditors; (i) if a
receiver, custodian, or trustee is appointed for the Premises or for all or
substantially all of the assets of Tenant or of any guarantor of this Lease,
which appointment is not vacated within sixty (60) days following the date of
such appointment; or (j) if Tenant fails to perform or observe any other terms
of this Lease and such failure shall continue for more than thirty (30) days
after Landlord gives Tenant notice of such failure, or, if such failure cannot
be corrected within such thirty (30) day period, if Tenant does not commence to
correct such default within said thirty (30) day period and thereafter
diligently prosecute the correction of same to completion within a reasonable
time and in any event prior to the time a failure to complete such correction
could cause Landlord to be subject to prosecution for violation of any law,
rule, ordinance or regulation or causes, or could cause, a default under any
mortgage, underlying lease, tenant leases or other agreements applicable to the
Premises.

      Section 13.2 Upon the occurrence of any Event of Default, Landlord shall
have the right, at Landlord's option, to elect to do any one or more of the
following without further notice or demand to Tenant, Tenant hereby expressly
waiving the requirement of service of any statutory notice or demand as a
condition precedent to Landlord's exercising any of the following rights: (a)
terminate this Lease, in which event Tenant shall immediately surrender the
Premises to Landlord, and, if Tenant fails to so surrender, Landlord shall have
the right, upon court order establishing an Event of Default, to enter upon and
take possession of the Premises and to expel or remove Tenant and its effects
without being liable for prosecution or any claim for damages therefor; and
Tenant shall, and hereby agrees to, indemnify Landlord for all loss and damage
which Landlord suffers by reason of

                                                                              23
<PAGE>

such termination, including damages in an amount equal to the total of (1) the
costs of recovering the Premises and all other expenses incurred by Landlord in
connection with Tenant's default; (2) the unpaid Rent earned as of the date of
termination, plus interest at the Interest Rate; (3) the total Rent which
Landlord would have received under this Lease for the remainder of the Term, but
discounted to the then present value at a rate of eight percent (8%) per annum,
minus the fair market rental value on a net basis of the balance of the Term as
of the time of such default, discounted to the then present value at a rate of
eight percent (8%) per annum (but in no event shall the result thereof be less
than zero for the purposes of this Section); and (4) all other sums of money and
damages owing by Tenant to Landlord; or (b) enter upon and take possession of
the Premises without terminating this Lease and without being liable to
prosecution or any claim for damages therefor, and, if Landlord elects, relet
the Premises on such terms as Landlord deems advisable, in which event Tenant
shall pay to Landlord on demand the cost of repossession, renovating, repairing
and altering the Premises for a new tenant or tenants and any deficiency between
the Rent payable hereunder and the rent paid under such reletting; provided,
however, that Tenant shall not be entitled to any excess payments received by
Landlord from such reletting. Landlord's failure to relet the Premises shall not
release or affect Tenant's liability for Rent or for damages; or (c) enter the
Premises without terminating this Lease and without being liable for prosecution
or any claim for damages therefor and maintain the Premises and repair or
replace any damage thereto or do anything for which Tenant is responsible
hereunder. Tenant shall reimburse Landlord immediately upon demand for any
reasonable expenses which Landlord incurs in thus effecting Tenant's compliance
under this Lease, and Landlord shall not be liable to Tenant for any damages
with respect thereto.

      Section 13.3 No agreement to accept a surrender of the Premises and no act
or omission by Landlord or Landlord's agents during the Term shall constitute an
acceptance or surrender of the Premises unless made in writing and signed by
Landlord. No re-entry or taking possession of the Premises by Landlord shall
constitute an election by Landlord to terminate this Lease unless a written
notice of such intention is given to Tenant. No provision of this Lease shall be
construed as an obligation upon Landlord to mitigate Landlord's damages under
the Lease.

      Section 13.4 No provision of this Lease shall be deemed to have been
waived by Landlord unless such waiver is in writing and signed by Landlord.
Landlord's acceptance of Rent following an Event of Default hereunder shall not
be construed as a waiver of such Event of Default. No custom or practice which
may grow up between the parties in connection with the terms of this Lease shall
be construed to waive or lessen Landlord's right to insist upon strict
performance of the terms of this Lease, without a written notice thereof to
Tenant from Landlord.

      Section 13.5 The rights granted to Landlord in this Article 13 shall be
cumulative of every other right or remedy provided in this Lease or which
Landlord may otherwise have at law or in equity or by statute, and the exercise
of one or more rights or remedies shall not prejudice or impair the concurrent
or subsequent exercise of other rights or remedies or constitute a forfeiture or
waiver of Rent or damages accruing to Landlord by reason of any Event of Default
under this Lease. Tenant agrees to pay to Landlord all costs and expenses
incurred by Landlord in connection with an Event of Default and the enforcement
of this Lease, including all attorneys' fees incurred in connection with the
collection of any sums due hereunder or the enforcement of any right or remedy
of Landlord.

                                                                              24

<PAGE>

                                   ARTICLE 14

                                    INSURANCE

      Section 14.1 A. Tenant, at its sole expense, shall obtain and keep in
force during the Term the following insurance: (a) "All Risk" insurance insuring
Tenant's interest in all property located in the Premises, including furniture,
equipment, fittings, installations, fixtures, supplies and any other personal
property, leasehold improvements and alterations ("Tenant's Property"), in an
amount equal to the full replacement value, it being understood that no lack or
inadequacy of insurance by Tenant shall in any event make Landlord subject to
any claim by virtue of any theft of or loss or damage to any uninsured or
inadequately insured property; (b) Business Interruption insurance in an amount
that will reimburse Tenant for direct or indirect loss of earnings attributable
to all perils insured against under Section 14.1(a) or attributable to the
prevention of access to the Premises by civil authority; and sufficient to
reimburse Tenant for Rent in the event of a casualty to, or temporary taking of,
the Building or the Premises; (c) Commercial General Public Liability insurance
including personal injury, bodily injury, broad form property damage, operations
hazard, owner's protective coverage, contractual liability, with a cross
liability clause and a severability of interests clause to cover Tenant's
indemnities set forth herein, and products and completed operations liability,
in limits not less than $5,000,000.00 inclusive per occurrence or such higher
limits as Landlord may require from time to time during the Term; (d) Worker's
Compensation and Employer's Liability insurance, with a waiver of subrogation
endorsement, in form and amount as required by applicable law; and (e) In the
event Tenant performs any repairs or alterations in the Premises, Builder's Risk
insurance on an "All Risk" basis (including collapse) on a completed value
(non-reporting) form for full replacement value covering all work incorporated
in the Building and all materials and equipment in or about the Premises; (f)
Tenant's "All Risk" Legal Liability insurance for the replacement cost value of
the Premises; and (g) any other form or forms of insurance or any changes or
endorsements to the insurance required herein as Landlord, or any mortgagee or
lessor of Landlord may reasonably require, from time to time, in form or in
amount.

            B. Tenant shall have the right to include the insurance required by
Section 14.1A under Tenant's policies of "blanket insurance," provided that no
other loss which may also be insured by such blanket insurance shall affect the
insurance coverages required hereby and further provided that Tenant delivers to
Landlord a certificate specifically stating that such coverages apply to
Landlord, and the Premises. All such policies of insurance or certificates
thereof shall name Tenant as named insured thereunder and shall name Landlord
and all mortgagees and lessors of Landlord of which Tenant has been notified, as
additional insureds, all as their respective interest may appear. All such
policies or certificates shall be issued by insurers acceptable to Landlord and
in form satisfactory to Landlord. Tenant shall deliver to Landlord certificates
with copies of policies, together with satisfactory evidence of payment of
premiums for such policies, by the Commencement Date and, with respect to
renewals of such policies, not later than thirty (30) days prior to the end of
the expiring term of coverage. Upon Landlord's request Tenant shall deliver to
Landlord certified copies of such policies. All policies of insurance shall be
primary and Tenant shall not carry any separate or additional insurance
concurrent in form or contributing in the event of any loss or damage with any
insurance required to be maintained by Tenant under this Lease. All such
policies and certificates shall contain an agreement by the insurers that the
policies will not be

                                                                              25
<PAGE>

invalidated as they affect the interests of Landlord and Landlord's mortgagees
by reason of any breach or violation of warranties, representations,
declarations or conditions contained in the policies and that the insurers shall
notify Landlord and any mortgagee or lessor of Landlord in writing, by
Registered U.S. mail, return receipt requested, not less than thirty (30) days
before any material change, reduction in coverage, cancellation, including
cancellation for nonpayment of premium, or other termination thereof or change
therein and shall include a clause or endorsement denying the insurer any rights
or subrogation against Landlord, if such clause or endorsement is available
without additional cost to Tenant.

      Section 14.2 Landlord shall insure the Building against damage with
casualty (with limits of not less than 90% of replacement cost) and commercial
general public liability insurance (with such limit as Landlord reasonably deems
appropriate), with such deductible as Landlord reasonably deems appropriate and
is consistent with the deductibles carried by prudent landlords on similar
buildings in the metropolitan Chicago, Illinois area. Notwithstanding any
contribution by Tenant to the cost of insurance premiums, as provided
hereinabove, Landlord shall not be required to carry insurance of any kind on
Tenant's Property, and Tenant hereby agrees that Tenant shall have no right to
receive any proceeds from any insurance policies carried by Landlord.

      Section 14.3 Tenant shall not conduct or knowingly permit to be conducted
in the Premises any activity, or place any equipment in or about the Premises or
the Building, which will invalidate the insurance coverage in effect or increase
the rate of fire insurance or other insurance on the Premises or the Building,
and Tenant shall comply with all requirements and regulations of Landlord's
casualty and liability insurer. If any invalidation of coverage or increase in
the rate of fire insurance or other insurance occurs or is threatened by any
insurance company due to any act or omission by Tenant, or its agents,
employees, representatives, or contractors, such statement or threat shall be
conclusive evidence that the increase in such rate is due to such act of Tenant
or the contents or equipment in or about the Premises, and, as a result thereof,
Tenant shall be liable for such increase and shall be considered Additional Rent
payable with the next monthly installment of Base Rent due under this Lease. In
no event shall Tenant introduce or permit to be kept on the Premises or brought
into the Building any dangerous, noxious, radioactive or explosive substance.

      Section 14.4 Landlord and Tenant each hereby waive any right of
subrogation and right of recovery or cause of action for injury or loss to the
extent that such injury or loss is covered by fire, extended coverage, "All
Risk" or similar policies covering real property or personal property (or which
would have been covered if Tenant or Landlord, as the case may be, was carrying
the insurance required by this Lease). Said waivers shall be in addition to, and
not in limitation or derogation or, any other waiver or release contained in
this Lease. Written notice of the terms of the above mutual waivers shall be
given to the insurance carriers of Landlord and Tenant and the parties'
insurance policies shall be properly endorsed, if necessary, to prevent the
invalidation of said policies by reason of such waivers.

                                                                              26
<PAGE>

                                   ARTICLE 15

                          DAMAGE BY FIRE OR OTHER CAUSE

      Section 15.1 If the Premises or any portion thereof is damaged or
destroyed by any casualty and such damage renders all or a substantial portion
of the Premises untenantable, Landlord shall deliver to Tenant within sixty (60)
days of such damage or destruction an estimate of the duration of the period in
which the Premises will be untenantable, as reasonably determined by Landlord.
If such estimated period shall be for more than twelve (12) months from the date
of such damage, Landlord or Tenant shall have the right, at Landlord's or
Tenant's option, to terminate this Lease by giving Tenant or Landlord, as
applicable, notice of such termination, within fifteen (15) days after the date
of delivery to Tenant of Landlord's repair duration estimate.

      Section 15.2 In the event of destruction or damage to the Premises which
is not subject to or does not result in a termination under Section 15.1, this
Lease shall not terminate and Rent shall be abated in proportion to the area of
the Building which, in Landlord's reasonable opinion, cannot be used or occupied
by Tenant as a result of such casualty. Landlord shall in such event, within a
reasonable time after the date of such destruction or damage, subject to force
majeure (as defined in Section 25.6) and to the extent and availability of
insurance proceeds, restore the Premises to as near the same condition as
existed prior to such partial damage or destruction. In no event shall any
termination occur if damage to or destruction of the Premises is the result of
the negligence or willful act of Tenant, or Tenant's agents, employees,
contractors, licensees or invitees.

      Section 15.3 If the Premises or any material portion thereof is destroyed
by fire or other causes at any time during the last year of the Term and Tenant
is unable to operate its business in the Premises as a result thereof, then
either Landlord or Tenant shall have the right, at the option of either party,
to terminate this Lease by giving written notice to the other within sixty (60)
days after the date of such destruction.

      Section 15.4 Landlord shall have no liability to Tenant for inconvenience,
loss of business, or annoyance arising from any repair of any portion of the
Premises or the Building. If Landlord is required by this Lease or by any
mortgagee or lessor of Landlord to repair or if Landlord undertakes to repair,
Tenant shall pay to Landlord that amount of Tenant's insurance proceeds (or the
amount which would have been received by Tenant if Tenant was carrying the
insurance required by this Lease) which insures such damage as a contribution
towards such repair, and Landlord shall use reasonable efforts to have such
repairs made promptly and in a manner which will not unnecessarily interfere
with Tenant's occupancy.

      Section 15.5 In the event of termination of this Lease pursuant to
Sections 15.1 or 15.3, then all Rent shall be apportioned and paid to the date
on which possession is relinquished or the date of such damage, whichever last
occurs, and Tenant shall immediately vacate the Premises according to such
notice of termination; provided, however, that those provisions of this Lease
which are designated to cover matters of termination and the period thereafter
shall survive the termination hereof.

                                                                              27
<PAGE>

                                   ARTICLE 16

                                  CONDEMNATION

      Section 16.1 In the event the whole or substantially the whole of the
Building or the Premises are taken or condemned by eminent domain or by any
conveyance in lieu thereof (such taking, condemnation or conveyance in lieu
thereof being hereinafter referred to as "condemnation"), the Term shall cease
and this Lease shall terminate on the earlier of the date the condemning
authority takes possession or the date title vests in the condemning authority.

      Section 16.2 In the event any portion of the Building shall be taken by
condemnation, which taking, in Landlord's judgment, is such that the Building
cannot be restored in an economically feasible manner for use substantially as
originally designed, then Landlord shall have the right, at Landlord's option,
to terminate this Lease, effective as of the date specified by Landlord in a
written notice of termination from Landlord to Tenant.

      Section 16.3 In the event that a portion, but less than substantially the
whole, of the Premises shall be taken by condemnation, then this Lease shall be
terminated as of the date of such condemnation as to the portion of the Premises
so taken, and unless Landlord exercises its option to terminate this Lease
pursuant to Section 16.2, this Lease shall remain in full force and effect as to
the remainder of the Premises; provided that the Base Rent shall be abated in
proportion to the rentable area of the Building so taken.

      Section 16.4 In the event of termination of this Lease pursuant to the
provisions of Section 16.1 or 16.2, the Rent shall be apportioned as of such
date of termination; provided, however, that those provisions of this Lease
which are designated to cover matters of termination and the period thereafter
shall survive the termination hereof.

      Section 16.5 In the event that Landlord receives notice of a condemnation
proceeding, Landlord shall provide tenant with a copy of such notice promptly
upon receipt of such notice. All compensation awarded or paid upon a
condemnation of any portion of the Premises shall belong to and be the property
of Landlord without participation by Tenant. Nothing herein shall be construed,
however, to preclude Tenant from prosecuting any claim directly against the
condemning authority for loss of business, loss of good will, moving expenses,
damage to, and cost of removal of, trade fixtures, furniture and other personal
property belonging to Tenant and Landlord shall provide Tenant with reasonable
assistance with the same, provided Landlord shall not be made to incur any
out-of-pocket costs in connection herewith; and further provided, that Tenant
shall make no claim which shall diminish or adversely affect any award claimed
or received by Landlord.

      Section 16.6 If any portion of the Premises other than the Building or
parking areas is taken by condemnation or if the temporary use or occupancy (not
to exceed thirty (30) days) of all or any part of the Premises shall be taken by
condemnation during the Term, this Lease shall be and remain unaffected by such
condemnation, and Tenant shall continue to pay in full the Rent payable
hereunder. In the event of any such temporary taking for use or occupancy of all
or any part of the Premises, Tenant shall be entitled to appear, claim, prove
and receive the portion of the award for

                                                                              28
<PAGE>

such taking that represents compensation for use or occupancy of the Premises
during the Term and Landlord shall be entitled to appear, claim, prove and
receive the portion of the award that represents the cost of restoration of the
Premises and the use or occupancy of the Premises after the end of the Term
hereof. In the event of any such condemnation of any portion of the Premises
other than the Building and parking areas, Landlord shall be entitled to appear,
claim, prove and receive all of that award.

                                   ARTICLE 17

                                 INDEMNIFICATION

      Section 17.1 Tenant hereby waives all claims against Landlord, its agents,
employees, representatives and contractors for damage to any property or injury
to, or death of, any person in, upon, or about the Premises, arising at any time
and from any cause other than primarily and to the extent by reason of the gross
negligence or willful misconduct of Landlord, its agents, employees,
representatives, or contractors. Tenant shall, and hereby agrees to, indemnify
and hold Landlord, its agents, employees, representatives and contractors
harmless from any damage to any property or injury to, or death of, any person
arising from the use or occupancy of the Premises by Tenant, its agents,
employees, representatives, contractors, successors, assigns, licensees, or
invitees, unless and to the extent such damage is caused primarily by the
negligence or willful misconduct of Landlord, its agents, employees,
representatives, or contractors. Without limiting the generality of the
foregoing, except as provided in Section 17.2, Landlord, its agents, employees,
representatives and contractors shall not be liable for any injury or damage to
persons or property resulting from the condition or design of, or any defective,
Building or its mechanical systems or equipment which may exist or occur or from
any fire, smoke, explosion, falling plaster, steam, gas, electricity, water,
rain, flood, snow, or leaks from any part of the Premises or from the pipes,
appliances, plumbing works, roof, or subsurface of any floor or ceiling, or from
the street or any other place, or by dampness or by any other similar cause
unless and to the extent the same is caused primarily by the gross negligence or
willful misconduct of Landlord, its agents, employees, representatives or
contractors. Landlord, its agents, employees, representatives and contractors
shall not be liable to Tenant for any such damage caused by other occupants of
property adjacent to the Premises, or by the public, or caused by construction
(unless and to the extent caused primarily by the gross negligence or willful
misconduct of Landlord) or by any private, public or quasi-public work. Tenant's
foregoing indemnity shall include reasonable attorneys' fees, investigation
costs, and all other reasonable costs and expenses incurred by Landlord, its
agents, employees, representatives and contractors in any connection therewith.
The provisions of this Article 17 shall survive the expiration or termination of
this Lease with respect to any damage, injury, or death occurring before such
expiration or termination. If Landlord , its agents, employees, representatives
and contractors are made a party to any litigation commenced by or against
Tenant or relating to this Lease or to the Premises, and provided that in any
such litigation Landlord, its agents, employees, representatives or contractors
are not finally adjudicated to be primarily at fault, then Tenant shall pay all
costs and expenses, including attorneys' fees and court costs, incurred by or
imposed upon Landlord, its agents, employees, representatives or contractors
because of any such litigation, and the amount of all such costs and expenses,
including attorneys' fees and court costs, shall be a demand obligation owing by
Tenant to Landlord, its agents, employees, representatives and contractors.
Notwithstanding

                                                                              29
<PAGE>

anything in this Article 17 to the contrary, Landlord its agents, employees,
representatives and contractors shall not be liable to Tenant for any claims
resulting from the gross negligence or willful misconduct of Landlord, its
agents, employees, representatives, or contractors to the extent such claims are
covered by the types of insurance Tenant is to maintain pursuant to Section
14.1A.

      17.2 Landlord shall defend, indemnify and hold Tenant, its employees,
shareholders, agents and representatives harmless from and against any breach of
the representations and warranties set forth in Section 6.1, damage to property
or injury to, or death of, any person arising from the gross negligence or
willful misconduct of Landlord.

                                   ARTICLE 18

                    SUBORDINATION AND ESTOPPEL CERTIFICATES

      Section 18.1 This Lease and all rights of Tenant hereunder are subject and
subordinate to any deeds to secure debt, mortgages, or other security
instruments which now or hereafter cover all or any portion of the Premises or
any interest of Landlord therein, and to any advances made on the security
thereof, and to any increases, renewals, modifications, consolidations,
replacements, and extensions of any of such mortgages. Landlord shall use
reasonable efforts to cause the holder of any mortgage encumbering the Premises
as of the date of this Lease to execute and deliver to Tenant a subordination,
non-disturbance and attornment agreement in such holder's current form with
Tenant responsible for all costs imposed by such holder to prepare or execute
same. If Landlord fails to cause such holder to execute and deliver such
agreement, Tenant shall have no right to terminate this lease. This provision is
declared by Landlord and Tenant to be self- operative and no further instrument
shall be required to effect such subordination of this Lease. Upon demand,
Tenant shall execute, acknowledge, and deliver to Landlord any further
instruments and certificates evidencing such subordination as Landlord, and any
mortgagee or lessor of Landlord shall reasonably require, and if Tenant fails to
so execute, acknowledge and deliver such instruments within ten (10) Business
Days after Landlord's request, Landlord is hereby empowered to do so in Tenant's
name and on Tenant's behalf; Tenant hereby irrevocably appoints Landlord as
Tenant's agent and attorney-in-fact for the purpose of executing, acknowledging,
and delivering any such instruments and certificates. Tenant shall not
unreasonably withhold, delay, or defer its written consent to reasonable
modifications in this Lease which are a condition of any construction, interim
or permanent financing for the Premises or any reciprocal easement agreement
with facilities in the vicinity of the Building, provided that such
modifications do not increase the obligations of Tenant hereunder or materially
and adversely affect Tenant's use and enjoyment of the Premises. This Lease is
further subject and subordinate to: (a) all applicable ordinances of any
government authority having jurisdiction over the Premises, relating to
easements, franchises, and other interests or rights upon, across, or
appurtenant to the Premises; and (b) all utility easements and agreements, now
or hereafter created for the benefit of the Premises.

      Section 18.2 Notwithstanding the generality of the foregoing provisions of
Section 18.1, any mortgagee or lessor of Landlord shall have the right at any
time to subordinate any such mortgage or underlying lease to this Lease, or to
any of the provisions hereof, on such terms and subject to such conditions as
such mortgagee or lessor of Landlord may consider appropriate in its

                                                                              30
<PAGE>

discretion. At any time, before or after the institution of any proceedings for
the foreclosure of any such mortgage, or the sale of the Building under any such
mortgage, or the termination of any underlying lease, Tenant shall, upon request
of such mortgagee or any person or entities succeeding to the interest of such
mortgagee or the purchaser at any foreclosure sale ("Successor Landlord"),
automatically become the Tenant (or if the Premises has been validly subleased,
the subtenant) of the Successor Landlord, without change in the terms or other
provisions of this Lease (or, in the case of a permitted sublease, without
change in this Lease or in the instrument setting forth the terms of such
sublease); provided, however, that the Successor Landlord shall not be (i) bound
by any payment made by Tenant of Rent or Additional Rent for more than one (1)
month in advance, except for a Security Deposit previously paid to Landlord (and
then only if such Security Deposit has been deposited with and is under the
control of the Successor Landlord), (ii) liable for any damages or subject to
any offset or defense by Tenant to the payment of Rent by reason of any act or
omission of any prior landlord (including Landlord), or (iv) personally or
corporately liable, in any event, beyond the limitations on landlord liability
set forth in Section 25.5 of this Lease. This agreement of Tenant to attorn to a
Successor Landlord shall survive any such foreclosure sale, trustee's sale
conveyance in lieu thereof. Tenant shall upon demand at any time, before or
after any such foreclosure or termination execute, acknowledge, and deliver to
the Successor Landlord any written instruments and certificates evidencing such
attornment as such Successor Landlord may reasonably require; provided, however,
that Landlord shall use its reasonable efforts to require that such agreement
provide that upon such attornment as long as Tenant is not in default hereunder,
Tenant's possession of the Premises under this Lease shall not be disturbed.

      Section 18.3 Tenant shall, from time to time, within ten (10) Business
Days after request from Landlord, or from any mortgagee or lessor of Landlord,
execute, acknowledge and deliver in recordable form a certificate certifying, to
the extent true, that this Lease is in full force and effect and unmodified (or,
if there have been modifications, that the same is in full force and effect as
modified and stating the modifications); that the Term has commenced and the
full amount of the Rent then accruing hereunder; the dates to which the Rent has
been paid; that Tenant has accepted possession of the Premises and that any
improvements required by the terms of this Lease to be made by Landlord have
been completed to the satisfaction of Tenant; the amount, if any, that Tenant
has paid to Landlord as a Security Deposit; that no Rent under this Lease has
been paid more than thirty (30) days in advance of its due date; that the
address for notices to be sent to Tenant is as set forth in this Lease (or has
been changed by notice duly given and is as set forth in the certificate); that
Tenant, as of the date of such certificate, has no charge, lien, or claim of
offset under this Lease or otherwise against Rent or other charges due or to
become due hereunder; that, to the knowledge of Tenant, Landlord is not then in
default under this Lease; and such other matters as may be reasonably requested
by Landlord or any mortgagee or lessor of Landlord. Any such certificate may be
relied upon by Landlord, any Successor Landlord, or any mortgagee or lessor of
Landlord. Landlord agrees periodically to furnish, when reasonably requested in
writing by Tenant, certificates signed by Landlord containing information
similar to the foregoing information.

      Section 18.4 No act or failure to act on the part of Landlord which would
entitle Tenant under the terms of this Lease, or by law, to be relieved of
Tenant's obligations hereunder or to terminate this Lease, shall result in a
release of such obligations or a termination of this Lease unless (a) Tenant has
given notice by registered or certified mail to any mortgagee or lessor of
Landlord

                                                                              31
<PAGE>

whose address shall have been furnished to Tenant, and (b) Tenant offers such
mortgagee or lessor of Landlord a reasonable opportunity to cure the default,
including time to obtain possession of the Premises by power of sale or judicial
foreclosure, if such should prove necessary to effect a cure.

                                   ARTICLE 19

                            SURRENDER OF THE PREMISES

      Section 19.1 Upon the Expiration Date or earlier termination of this
Lease, or upon any re-entry of the Premises by Landlord without terminating this
Lease pursuant to Section 13.2(b), Tenant, at Tenant's sole cost and expense,
shall peacefully vacate and surrender the Premises to Landlord in good order,
broom clean and in the same condition as at the beginning of the Term or as the
Premises may thereafter have been improved by Landlord or Tenant (provided that
Tenant's improvements were made with Landlord's consent), reasonable use and
wear thereof and repairs which are Landlord's obligations under Articles 9, 15
and 16 only excepted, and Tenant shall remove all of Tenant's Property and turn
over all keys for the Premises to Landlord. Should Tenant continue to hold the
Premises after the expiration or earlier termination of this Lease, such holding
over, unless otherwise agreed to by Landlord in writing, shall constitute and be
construed as a tenancy at sufferance at monthly installments of Rent equal the
greater of two hundred percent (200%) of the monthly portion of Rent in effect
as of the date of expiration or earlier termination or two hundred percent
(200%) of the fair market rental value of the Premises, and subject to all of
the other terms, charges and expenses set forth herein except any right to renew
this Lease or to expand the Premises or any right to additional services. Tenant
shall also be liable to Landlord for all damage which Landlord suffers because
of any holding over by Tenant, and Tenant shall indemnify Landlord against all
claims made by any other tenant or prospective tenant against Landlord resulting
from delay by Landlord in delivering possession of the Premises to such other
tenant or prospective tenant. The provisions of this Article 19 shall survive
the expiration or earlier termination of this Lease.

                                   ARTICLE 20

                           LANDLORD'S RIGHT TO INSPECT

      Section 20.1 Landlord shall retain duplicate keys, cards, access codes or
other access means to all doors of the Premises. Landlord shall have the right
to enter the Premises at reasonable hours (or, in the event of an emergency, at
any hour) (a) to exhibit the same to present or prospective mortgagees, lessors
or purchasers during the Term and to prospective tenants during the last year of
the Term, (b) to inspect the Premises, (c) to confirm that Tenant is complying
with all of Tenant's covenants and obligations under this Lease, (d) to clean or
make repairs required of Landlord under the terms of this Lease, and (e) to
repair and service utility lines or other components of the Building; provided,
however, Landlord shall use reasonable efforts to minimize interference with
Tenant's business. Landlord shall not be liable to Tenant for the exercise of
Landlord's rights under this Article 21 and Tenant hereby waives any claims for
damages for any injury, inconvenience or interference with Tenant's business,
any loss of occupancy or quiet enjoyment of the Premises, and any other loss
occasioned thereby.

                                                                              32
<PAGE>

                                   ARTICLE 21

                             ROOF SPACE AND SIGNAGE

      Section 21.1 Subject to the provisions of Section 21.2 below, Landlord
reserves the right to license or lease space on the roof of the Building to
parties other than Tenant for the purpose of installing satellites, antennae and
other similar equipment, together with the right to install as reasonably
necessary equipment related thereto in the mechanical rooms of the Building and
the right to access all such equipment on the roof and in the mechanical rooms
of the Building with all necessary wiring.

      Section 21.2 Tenant shall have the right to install, at Tenant's sole cost
and expense, on the roof of the Building two (2) satellite dishes with a
diameter of 36 inches or smaller and related accessories (collectively,
"Satellite Equipment") as Tenant may reasonably request, provided that such
Satellite Equipment is properly screened, does not damage the structural
integrity of the Premises, shall not involve the making of any roof penetrations
or any other actions which would result in a breach of Landlord's roof warranty,
does not interfere with any other equipment on the roof, shall comply with
Applicable Laws and further provided that Tenant provides Landlord, at least
twenty (20) days prior to any such installation, (i) plans and specifications
for the installation of the Satellite Equipment, which shall be subject to
Landlord's prior written approval, which approval shall not be unreasonably
withheld or delayed; and (ii) copies of all required governmental and
quasi-governmental permits, licenses and authorizations which Tenant shall
obtain at its own expense. Tenant acknowledges that, upon the expiration or
termination of this Lease, Tenant shall be responsible, at its sole cost and
expense, to remove the Satellite Equipment and repair any and all damage as a
result thereof.

      Section 21.3 Provided Tenant obtain all government approvals required in
connection herewith, upon execution of this Lease, Tenant shall have the right
to place its name (in lieu of the Premark name) on the currently existing
monument at the Premises using signage of a style and size which is
substantially the same as the existing signage.

                                   ARTICLE 22

                                    BROKERAGE

      Section 22.1 Tenant and Landlord each represent and warrant to the other
that it has not entered into any agreement with, or otherwise had any dealings
with, any broker or agent in connection with the negotiation or execution of
this Lease which could form the basis of any claim by any such broker or agent
for a brokerage fee or commission, finder's fee, or any other compensation of
any kind or nature in connection herewith, other than with Broker, and each
party shall, and hereby agrees to, indemnify and hold the other harmless from
all costs (including court costs, investigation costs, and attorneys' fees),
expenses, or liability for commissions or other compensation claimed by any
broker or agent with respect to this Lease which arise out of any agreement or
dealings, or alleged agreement or dealings, between the indemnifying party and
any

                                                                              33
<PAGE>

such agent or broker, other than with Broker. This provision shall survive the
expiration or earlier termination of this Lease.

                                   ARTICLE 23

                       OBSERVANCE OF RULES AND REGULATIONS

      Section 23.1 Tenant and Tenant's servants, employees, agents, visitors,
and licensees shall observe faithfully and comply strictly with all Rules and
Regulations (herein so called) attached to this Lease as such Rules and
Regulations may be changed from time to time. Landlord shall at all times have
the right to make reasonable changes in and additions to such Rules and
Regulations; provided Landlord gives Tenant prior notice of such changes and
provided that such new rules and regulations or changes in existing rules and
regulations do not conflict with this Lease, and do not materially interfere
with the lawful conduct of Tenant's business in the Premises. Any failure by
Landlord to enforce any of the Rules and Regulations now or hereafter in effect
against Tenant shall not constitute a waiver of any such Rules and Regulations.

                                   ARTICLE 24

                                     NOTICES

      Section 24.1 All notices, consents, demands, requests, documents, or other
communications (other than payment of Rent) required or permitted hereunder
(collectively, "notices") shall be in writing and be deemed given, whether
actually received or not, when dispatched for hand delivery (with signed
receipts) to the other party, or on the first Business Day after dispatched for
delivery by air express courier (with signed receipts) to the other party, or on
the second Business Day after deposit in the United States mail, postage
prepaid, certified, return receipt requested, except for notice of change of
address which shall be deemed given only upon actual receipt. The addresses of
the parties for notices are set forth in Article 1, or any such other addresses
subsequently specified by each party in notices given pursuant to this Section
24.1.

                                   ARTICLE 25

                                  MISCELLANEOUS

      Section 25.1 PROFESSIONAL FEES. In any action or proceeding brought by
either party against the other under this Lease, the prevailing party shall be
entitled to recover from the other party its professional fees for attorneys,
appraisers and accountants, its investigation costs, and any other legal
expenses and court costs incurred by the prevailing party in such action or
proceeding.

      Section 25.2 REIMBURSEMENTS. Wherever the Lease requires Tenant to
reimburse Landlord for the cost of any item, such costs will be the reasonable
and customary charge periodically established by Landlord for such item.
Landlord shall keep in its manager's office a schedule of such charges (which
Landlord may periodically change) for Tenant's examination. The

                                                                              34
<PAGE>

schedule of charges may include, at the discretion of Landlord, a reasonable
allocation of overhead, administrative, and related costs and a reasonable fee
for Landlord's agent or manager who performs such services or arranges for
performance of such services. All such charges shall be payable upon demand as
Additional Rent.

      Section 25.3 SEVERABILITY. Every agreement contained in this Lease is, and
shall be construed as, a separate and independent agreement. If any term of this
Lease or the application thereof to any person or circumstances shall be invalid
or unenforceable, the remaining agreements contained in this Lease shall not be
affected.

      Section 25.4 NON-MERGER. There shall be no merger of this Lease with any
ground leasehold interest or the fee estate in the Premises or any part thereof
by reason of the fact that the same person may acquire or hold, directly or
indirectly, this Lease or any interest in this Lease as well as any ground
leasehold interest or fee estate in the Premises or any interest in such fee
estate.

      Section 25.5 LANDLORD'S LIABILITY. Anything contained in this Lease to the
contrary notwithstanding, Tenant agrees that Tenant shall look solely to the
estate and property of Landlord in the Premises for the collection of any
judgment or other judicial process requiring the payment of money by Landlord
for any default or breach by Landlord under this Lease, subject, however, to the
prior rights of any mortgagee or lessor of the Premises. No other assets of
Landlord or any partners, shareholders, or other principals of Landlord shall be
subject to levy, execution or other judicial process for the satisfaction of
Tenant's claim.

      Section 25.6 FORCE MAJEURE. Whenever the period of time is herein
prescribed for action to be taken by Landlord or Tenant, Landlord or Tenant
shall not be liable or responsible for, and there shall be excluded from the
computation for any such period of time, any delays due to force majeure, which
term shall include strikes, riots, acts of God, shortages of labor or materials,
weather, war, governmental approvals, laws, regulations, or restrictions, or any
other cause of any kind whatsoever which is beyond the reasonable control of
Landlord or Tenant. Force majeure shall not excuse or delay Tenant's obligation
to pay Rent or any other amount due under this Lease.

      Section 25.7 HEADINGS. The article headings contained in this Lease are
for convenience only and shall not enlarge or limit the scope or meaning of the
various and several articles hereof. Words in the singular number shall be held
to include the plural, unless the context otherwise requires. All agreements and
covenants herein contained shall be binding upon the respective heirs, personal
representatives, and successors and assigns of the parties thereto.

      Section 25.8 SUCCESSORS AND ASSIGNS. All agreements and covenants herein
contained shall be binding upon the respective heirs, personal representatives,
successors and assigns or the parties hereto. If there is more than one Tenant,
the obligations hereunder imposed upon Tenant shall be joint and several. If
there is a guarantor of Tenant's obligations hereunder, Tenant's obligations
shall be joint and several obligations of Tenant and such guarantor, and
Landlord need not first proceed against Tenant hereunder before proceeding
against such guarantor, and any such guarantor shall not be released from its
guarantee for any reason, including any amendment of this Lease, any forbearance
by Landlord or waiver of any of Landlord's rights, the failure to give Tenant

                                                                              35
<PAGE>

or such guarantor any notices, or the release of any party liable for the
payment or performance of Tenant's obligations hereunder. Notwithstanding the
foregoing, nothing contained in this Section 26.9 shall be deemed to override
Article 8.

      Section 25.9 LANDLORD'S REPRESENTATIONS. Neither Landlord nor Landlord's
agents or brokers have made any representations or promises with respect to the
Building, the Land, or any other portions of the Premises except as herein
expressly set forth and all reliance with respect to any representations or
promises is based solely on those contained herein. No rights, easements, or
licenses are acquired by Tenant under this Lease by implication or otherwise
except as, and unless, expressly set forth in this Lease.

      Section 25.10 ENTIRE AGREEMENT; AMENDMENTS. This Lease and the Exhibits
and Riders attached hereto set forth the entire agreement between the parties
and cancel all prior negotiations, arrangements, brochures, agreements, and
understandings, if any, between Landlord and Tenant regarding the subject matter
of this Lease. No amendment or modification of this Lease shall be binding or
valid unless expressed in writing executed by both parties hereto.

      Section 25.11 GOVERNING LAW. This Lease shall be governed by and construed
under the laws of the State of Illinois. Any action brought to enforce or
interpret this Lease shall be brought in the court of appropriate jurisdiction
in Lake County, Illinois. Should any provision of this Lease require judicial
interpretation, Landlord and Tenant hereby agree and stipulate that the court
interpreting or considering same shall not apply the presumption that the terms
hereof shall be more strictly construed against a party by reason of any rule or
conclusion that a document should be construed more strictly against the party
who itself or through its agents prepared the same, it being agreed that all
parties hereto have participated in the preparation of this Lease and that each
party had full opportunity to consult legal counsel of its choice before the
execution of this Lease.

      Section 25.12 MANAGEMENT OFFICE. Landlord reserves the right to occupy a
management office in the Building at no charge to Landlord. Such office shall
not exceed 120 square feet and shall be in a location reasonably acceptable to
Landlord and Tenant. Landlord shall also be entitled to occupy one cubicle
workspace in proximity to the management office and reasonable use of conference
facilities in the Building.

      Section 25.13 ANCIENT LIGHTS. Any elimination or shutting off of light,
air, or view by any structure which may be erected on lands adjacent to the
Building shall in no way affect this Lease and Landlord shall have no liability
to Tenant with respect thereto.

      Section 25.14 CHANGES TO PREMISES BY LANDLORD. Upon notice to Tenant,
Landlord shall have the right to make reasonably required changes to all
portions of the Premises for the purpose of improving access or security to the
Premises or the flow of pedestrian and vehicular traffic therein.

      Section 25.15 TIME OF ESSENCE. Time is of the essence of this Lease.

      Section 25.16 LANDLORD'S ACCEPTANCE OF LEASE. The submission of this Lease
to Tenant shall not be construed as an offer and Tenant shall not have any
rights with respect thereto unless

                                                                              36
<PAGE>

Landlord executes a copy of this Lease and delivers the same to Tenant.

      Section 25.17 PERFORMANCE BY TENANT. All covenants and agreements to be
performed by Tenant under any of the terms of this Lease shall be performed by
Tenant, at Tenant's sole cost and expense, and without any abatement of Rent. If
Tenant shall fail to pay any Rent, other than Base Rent, required to be paid by
it hereunder or shall fail to perform any other act on its part to be performed
hereunder, and such failure shall continue for longer than the period of cure,
if any, permitted in Section 13.1, Landlord may, at its option, without waiving
or releasing Tenant from obligations of Tenant, make any such payment or perform
any such other act on behalf of Tenant. All sums so paid by Landlord and all
necessary incidental costs, together with interest thereon at the Interest Rate,
from the date of such payment by Landlord, shall be payable to Landlord on
demand. Tenant covenants to pay any such sums, and Landlord shall have (in
addition to any other right or remedy of Landlord) the same rights and remedies
in the event of the non-payment thereof by Tenant as in the case of default by
Tenant in the payment of Rent.

      Section 25.18 FINANCIAL STATEMENTS. At any time during the term of this
Lease, Tenant shall, upon ten (10) days prior written notice from Landlord,
provide Landlord with its current 10Q or 10K and such 10Qs or 10Ks of the two
(2) years prior or, if 10Qs and 10Ks are not available, quarterly financial
statements certified by Tenant and annual financial statements audited by a
certified public accountant; provided, however, if Tenant is acquired by or
merged with another party, to the extent such is permitted under Article 8,
Landlord agrees to accept the financial statements of the acquiror or merged
entity. Such financial statements shall be prepared in accordance with generally
accepted accounting principles.

      Section 25.19 STATUTE OF LIMITATIONS. Any claim, demand, right or defense
by Tenant that arises out of this Lease or the negotiations that preceded this
Lease shall be barred unless Tenant commences an action thereon, or interposes a
defense by reason thereof, within two (2) years after the date of the inaction,
omission, event, or action that gave rise to such claim, demand, right, or
defense. Tenant acknowledges and understands, after having consulted with his
legal counsel, that the purpose of this section is to shorten the period within
which Tenant would otherwise have to raise such claims, demands, rights or
defenses under applicable laws.

      Section 25.20 ELECTRONIC PAYMENTS. At Landlord's option, all payments due
under this Lease shall be made by electronic funds transfer to an account
designated in writing by Landlord.

                                   ARTICLE 26

                                EXTENSION OPTION

      Section 26.1 Subject to the provisions hereinafter set forth, Landlord
hereby grants to Tenant an option to extend the term of this Lease on the same
terms, conditions and provisions contained in this Lease, except as otherwise
provided herein, for one period of five (5) years (the "Renewal Period") after
the expiration of the Term, which Renewal Period shall commence on the day after
the Expiration Date (the "Renewal Period Commencement Date") and end on the day
before the fifth (5th) anniversary of the Renewal Period Commencement Date.

                                                                              37
<PAGE>

      Section 26.2 Said option shall be exercisable by written notice from
Tenant to Landlord of Tenant's election to exercise said option given not later
than the date which is fifteen (15) months prior to the Renewal Period
Commencement Date, time being of the essence. Once exercised, said option shall
be irrevocable. If Tenant's option is not so exercised, said option shall
thereupon expire.

      Section 26.3 Tenant may only exercise said option, and an exercise thereof
shall only be effective, if at the time of Tenant's exercise of said option and
on the Renewal Period Commencement Date this Lease is in full force and effect
and Tenant is not in default under this Lease, and (inasmuch as said option is
intended only for the benefit of the original Tenant named in this Lease) the
entire Premises are occupied by the original Tenant named herein and said Tenant
has not assigned this Lease or sublet any portion of the Premises. Without
limitation of the foregoing, no sublessee or assignee shall be entitled to
exercise said option, and no exercise of said option by the original Tenant
named herein shall be effective in the event said Tenant assigns this Lease or
subleases all or part of the Premises prior to the Renewal Period Commencement
Date.

      Section 26.4 Base Rent of the Premises payable during the Renewal Period
with respect to all space included in the Premises as of the Renewal Period
Commencement Date shall be equal to the Market Rental Rate (as hereinafter
defined). Landlord shall give Tenant written notice of the Market Rental Rate
within thirty (30) days following written request by Tenant made not earlier
than seventeen (17) months prior to the Renewal Period Commencement Date.

      Section 26.5 If Tenant has validly exercised said option, within thirty
(30) days after Tenant gives Landlord notice of the exercise of the option,
Landlord and Tenant shall enter into a written amendment to this Lease
confirming the terms, conditions and provisions applicable to the Renewal Period
as determined in accordance herewith, with such revisions to the rental
provisions of this Lease as may be necessary to conform such provisions to the
Market Rental Rate.

      Section 26.6 The term "Market Rental Rate" per square foot of rentable
area shall mean the Base Rent for comparable space in the Lake County office
sub-market of the metropolitan Chicago, Illinois office market then being
offered by owners of such comparable space to prospective tenants for terms
commencing on or about the Renewal Period Commencement Date, including annual
escalations of Base Rent, all as reasonably determined by Landlord.

      Section 26.7 Tenant shall not have any option to extend the terms of this
Lease beyond the expiration of the Renewal Period.

                                                                              38
<PAGE>

                                   ARTICLE 27

                                OTHER DEFINITIONS

      When used in this Lease, the terms set forth hereinbelow shall have the
following meanings: (a) "Business Days" shall mean Monday through Friday (except
for Holidays); (b) The words "day" or "days" shall refer to calendar days,
except where "Business Days" are specified. (c) The words "herein", "hereof",
"hereby", "hereunder" and words of similar import shall be construed to refer to
this Lease as a whole and not to any particular Article or Section thereof
unless expressly so stated. (d) The words "include" and "including" shall be
construed as if followed by the phrase "without being limited to." (e) Reference
to Landlord as having "no liability to Tenant" or being "without liability to
Tenant" or words of like import shall mean that Tenant is not entitled to
terminate this Lease, or to claim actual or constructive eviction, partial or
total, or to receive any abatement or diminution of rent, or to be relieved in
any manner of any of Tenant's other obligations hereunder, or to be compensated
for loss or injury suffered or to enforce any other right or kind of liability
whatsoever against Landlord under or with respect to this Lease or with respect
to Tenant's use or occupancy of the Premises. (f) A "repair" shall be deemed to
include such rebuilding, replacement and restoration as may be necessary to
achieve and maintain good working order and condition. (g) The "termination of
this Lease" and words of like import includes the expiration of the Term or the
cancellation of this Lease pursuant to any of the provisions of this Lease or to
law. Upon the termination of this Lease, the Term shall end at 11:59 p.m. on the
date of termination as if such date were the Expiration Date, and neither party
shall have any further obligation or liability to the other after such
termination except (i) as shall be expressly provided for in this Lease and (ii)
for such obligations as by their nature or under the circumstances can only be,
or by the provisions of this Lease, may be, performed after such termination
and, in any event, unless expressly otherwise provided in this Lease, any
liability for a payment (which shall be apportioned as of the date of such
termination) which shall have accrued to or with respect to any period ending at
the time of termination shall survive the termination of this Lease. (h) The
"terms of this Lease" shall be deemed to include all terms, covenants,
conditions, provisions, obligations, limitations, restrictions, reservations and
agreements contained in this Lease. (i) "Tenant" shall be deemed to include
Tenant's successors and assigns (to the extent permitted by Landlord) and any
and all occupants of the Premises permitted by Landlord and claiming by, through
or under Tenant. (j) A "year" shall mean a calendar year. (k) "Central" shall
mean the heat, ventilating and air conditioning, life safety, electrical
distribution, plumbing, elevator and other major mechanical systems in the
Building.

                                                                              39
<PAGE>

                                   ARTICLE 28

                             WAIVER OF TRIAL BY JURY

      TENANT HEREBY WAIVES, TO THE FULLEST EXTENT PERMITTED BY LAW, THE RIGHT TO
TRIAL BY JURY IN ANY ACTION, PROCEEDING OR COUNTERCLAIM FILED BY EITHER PARTY,
WHETHER IN CONTRACT, TORT OR OTHERWISE, RELATING DIRECTLY OR INDIRECTLY TO THE
LEASE, THE PREMISES, THE PREMISES, OR ANY ACTS OF LANDLORD OR TENANT IN
CONNECTION THEREWITH.

                                   ARTICLE 29

                                 EXISTING LEASE

      Section 29.1 TERMINATION. Landlord and Tenant are the current landlord and
tenant under that certain Office Lease (the "Existing Lease") dated June 20,
1996 between Deerfield Road Associates Limited Partnership and Dade
International Inc., pursuant to which Tenant currently occupies the second floor
of the Building. Effective as of 11:59 p.m. on March 31, 2000 (the "Termination
Date"), the Existing Lease is hereby terminated. As of the Termination Date, the
Existing Lease shall be deemed to be of no further force or effect and neither
party shall have any further liability to the other under the Existing Lease
except for liabilities arising or accruing on or before the Termination Date and
except as expressly provided in this Agreement, the terms of which shall survive
the termination of the Existing Lease as herein described.

      Section 29.2 CERTIFICATION BY TENANT. Tenant represents and warrants to
Landlord that the following are true as of the date hereof and will be true on
the Termination Date:

      a.    Tenant owns and holds the entire interest of "Tenant" under the
            Existing Lease;
      b.    There exist no subleases affecting the premises under the
            Existing Lease; and
      c.    Tenant has not assigned, transferred or encumbered Tenant's
            interest under the Existing Lease.

In the event of a breach of any of the foregoing representations, Tenant shall
indemnify and hold Landlord harmless against any loss, claim, liability, damage
or expense resulting therefrom.

      Section 29.3 SURVIVAL OF OBLIGATIONS. Notwithstanding anything to the
contrary contained herein, it is expressly understood and agreed by the parties
hereto that the waiver, insurance and indemnity obligations of Landlord and
Tenant under the Existing Lease, arising out of any acts or other matters
occurring on or prior to the Termination Date, shall survive the termination of
the Existing Lease as aforesaid. Also, Landlord and Tenant shall remain liable,
after such termination, for any prorated real estate tax and operating expense
adjustments relating to the portion of the term of the Existing Lease prior to
the Termination Date.

                                                                              40
<PAGE>

      IN WITNESS WHEREOF, Landlord and Tenant have set their hands and seals
hereunto and have caused this Lease to be executed by duly authorized officials
thereof, as of the day and year set forth on the cover page hereof.

                                    LANDLORD:

                                    PRENTISS PROPERTIES REAL ESTATE FUND I,
                                    L.P., a Delaware limited partnership

                                    By:   PRENTISS PROPERTIES REAL
                                          ESTATE FUND I, L.LC., a Delaware
                                          limited liability company, its
                                          general partner

                                    By:   PRENTISS PROPERTIES
                                          ACQUISITION PARTNERS, L.P.
                                          a Delaware limited partnership

                                          By:   PRENTISS PROPERTIES I, INC.,
                                                a Delaware corporation, its
                                                managing member

                                                By: /s/ L.T. Krueger
                                                   -----------------------------
                                                  Name:  L.T. Krueger
                                                      --------------------------
                                                  Title:  EVP
                                                       -------------------------

                                                By:  /s/ Michael E. Shack
                                                  ------------------------------
                                                  Name:  Michael E. Shack
                                                      --------------------------
                                                  Title: Vice President
                                                       -------------------------

                                    TENANT:

                                    DADE BEHRING, INC.,
                                    a Delaware corporation

                                    By:  /s/ Robert J. Maple
                                      ------------------------------------------
                                        Name:  Robert J. Maple
                                            ------------------------------------
                                        Title: SVP Human Resources
                                             -----------------------------------

<PAGE>

                                  SCHEDULE 2.1

                                      None

<PAGE>

                                  SCHEDULE 6.1

                                      None

<PAGE>

                                    EXHIBIT A

                                    THE LAND

<PAGE>

                                    EXHIBIT B

                                  RENT SCHEDULE

<TABLE>
<CAPTION>

LEASE YEAR                 BASE RENT PER ANNUM       BASE RENT PER MONTH
----------                 -------------------       -------------------
<S>                        <C>                       <C>

 1                         $2,344,368                $195,364

 2                         $2,413,320                $201,110

 3                         $2,482,272                $206,856

 4                         $2,551,224                $212,602

 5                         $2,620,176                $218,348

 6                         $2,689,128                $224,094

 7                         $2,758,080                $229,840

 8                         $2,827,032                $235,586

 9                         $2,895,984                $241,332

10                         $2,964,936                $247,078

11                         $3,033,888                $252,824

12                         $3,102,840                $258,570
</TABLE>

<PAGE>

                                    EXHIBIT C

                           FORM OF COMMENCEMENT NOTICE

      This Commencement Notice is delivered this _____ day of _______________,
19___, by Prentiss Properties Real Estate Fund I, L.P., a Delaware limited
partnership ("Landlord"), to Dade Behring, Inc., a Delaware corporation
("Tenant"), pursuant to the provisions of Section 3.3 of that certain Lease
Agreement (the "Lease") dated ____________________, 19___, by and between
Landlord and Tenant covering the Building known as 1717 Deerfield Road,
Deerfield, Illinois. All terms used herein with their initial letter capitalized
shall have the meaning assigned to such terms in the Lease.

                             W I T N E S S E T H:

      1.    That Tenant has accepted possession of the Premises.

      2. As of the date hereof, Landlord has fulfilled all of its duties of an
inducement nature, and is not in default in any manner in the performance of any
of the terms, covenants, or provisions of the Lease.

      3.    The Commencement Date of the Lease is the 1st  day of April,
2000, and the Expiration Date is the 31st day of March, 2012.

      4. The Base Rent shall be the amounts set forth on the Base Rent Schedule
with payments of Base Rent of $195,364, beginning April 1, 2000, subject,
however, to such increases as provided in the Lease.

START DATE       END DATE
M/D/YY           M/D/YY         YEARLY AMOUNT        MONTHLY AMOUNT
-----------------------------------------------------------------------

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

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

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

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

      5. Remittance of the foregoing payments shall be made on the first day of
each month in accordance with the terms and conditions of the Lease at the
following address:

      6. Operating costs are estimated each year and revised information shall
be provided to

<PAGE>

Tenant. Pursuant to Article 5 of the Lease, Tenant shall be responsible for
Tenant's Share of Operating Costs.

      IN WITNESS WHEREOF, this instrument has been duly executed by Landlord as
of the date first written above.

                                    LANDLORD:

                                    PRENTISS PROPERTIES REAL ESTATE FUND I,
                                    L.P., a Delaware limited partnership

                                    By:   PRENTISS PROPERTIES REAL ESTATE
                                          FUND I, L.LC., a Delaware limited
                                          liability company, its general
                                          partner

                                          By:   PRENTISS PROPERTIES II, INC.,
                                                a Delaware corporation, its
                                                managing member

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

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

                                    TENANT:

                                    DADE BEHRING, INC.,
                                    a Delaware corporation

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

<PAGE>

                                   RIDER NO. 1

                              RULES AND REGULATIONS

      1. Sidewalks, doorways, vestibules, halls, stairways and similar areas
shall not be obstructed by tenants or their officers, agents, servants, and
employees, or used for any purpose other than ingress and egress to and from the
Premises and for going from one part of the Building to another part of the
Building.

      2. Plumbing fixtures and appliances shall be used only for the purpose for
which constructed, and no sweepings, rubbish, rags, or other unsuitable material
shall be thrown or placed therein. The cost of repairing any stoppage or damage
resulting to any such fixtures or appliances from misuse on the part of a tenant
or such tenant's officers, agents, servants, and employees shall be paid by such
tenant.

      3. No signs, posters, advertisements, or notices shall be painted or
affixed on any of the windows or doors, or other part of the exterior of the
Building, except of such color, size, and style, and in such places, as shall be
first approved in writing by the building manager, with the exception of the
monument sign as specified in the Lease. Tenant may place signs or notices
inside the Building so long as they are not visible from the outside of the
Building.

      4. The Premises shall not be used for conducting any barter, trade,
peddling, or exchange of goods or sale through promotional give-away gimmicks or
any business involving the sale of second-hand goods, insurance salvage stock,
or fire sale stock, and shall not be used for any auction or pawnshop business,
any fire sale, bankruptcy sale, going-out-of- business sale, moving sale, bulk
sale, or any other business which, because of merchandising methods or
otherwise, would tend to lower the first-class character of the Building.

      5. Tenants shall not do anything, or permit anything to be done, in or
about the Building, or bring or keep anything therein, that will in any way
increase the possibility of fire or other casualty or obstruct or interfere with
the rights of, or otherwise injure or annoy, other tenants, or do anything in
conflict with the valid pertinent laws, rules, or regulations of any
governmental authority.

      6. Tenant shall not place a load upon any floor of the premises which
exceeds to floor load per square foot which such floor was designed to carry or
which is allowed by applicable building code. Landlord may prescribe the weight
and position of all safes and heavy installations which Tenant desires to place
in the premises so as properly to distribute the weight thereof. All damage done
to the Building by the improper placing of heavy items which overstress the
floor will be repaired at the sole expense of the Tenant.

      7. A tenant shall notify the building manager when safes or other heavy
equipment are to be taken into or out of the Building. Moving of such items
shall be done under the supervision of the building manager, after receiving
written permission from him/her. A tenant shall be required to use protective
coverings on walls, elevators and floors to prevent damage caused by the moving
of items

<PAGE>

in and out of the building.

      8.    Corridor doors, when not in use, shall be kept closed.

      9.    Each tenant shall cooperate with building employees in keeping
the premises neat and clean.

      10. Nothing shall be swept or thrown into the corridors, halls, elevator
shafts, or stairways. No birds, animals, or reptiles, or any other creatures,
shall be brought into or kept in or about the building.

      11. Should a tenant require telegraphic, telephonic, annunciator, or any
other communication service, Landlord will direct the electricians and
installers where and how the wires are to be introduced and placed, from the
point of entry to the Building through the risers and into the Tenant's
telephone closet.

      12.   Tenants shall not make or permit any improper noises or odors in
the Building.

      13. No equipment of any kind shall be operated on the premises that could
in any way interfere with other parties having rights in the Premises.

      14. Business machines and mechanical equipment belonging to Tenant which
cause noise and/or vibration that may be transmitted to the structure of the
Building so as to be objectionable to Landlord shall be placed and maintained by
Tenant, at Tenant's expense, in setting of cork, rubber, or spring type noise
and/or vibration eliminators sufficient to eliminate vibration and/or noise.

      15. Tenants shall not use or keep in the Building any inflammable or
explosive fluid or substance, or any illuminating material, unless it is battery
powered, UL approved.

      16. Tenants employees or agents, or anyone else who desires to enter the
Building after normal business hours, may be required to provide appropriate
identification and sign in upon entry, and sign out upon leaving, giving the
location during such person's stay and such person's time of arrival and
departure, and shall otherwise comply with any reasonable access control
procedures as Landlord and Tenant may agree upon from time to time.

      17.   Landlord has the right to evacuate the Building in event of
emergency or catastrophe.

      18. If any governmental license or permit shall be required for the proper
and lawful conduct of Tenant's business, Tenant, before occupying the Premises,
shall procure and maintain such license or permit and submit it for Landlord's
inspection. Tenant shall at all times comply with the terms of any such license
or permit.

      19. All locks and keys for entry doors and doors within the Premises shall
be provided by Landlord, at Tenant's cost, except the initial entry doors locks
and keys shall be at Landlord's cost.

<PAGE>

      20.   Landlord shall not be responsible for any loss or damage to any
personalty items of Tenants or their employees.

      21. Landlord and Tenant may agree upon revision to these Rules and
Regulations and make such other and further rules and regulations not
inconsistent with the express terms of the Lease as in the judgment of Landlord
and Tenant shall from time to time be needed for the safety, protection, care,
and cleanliness of the Building, the operation thereof, the preservation of good
order therein, and the protection and comfort of its tenants, their agents,
employees, and invitees, which Rules and Regulations when made and notice
thereof given to a tenant shall be binding upon him in like manner as if
originally herein prescribed. In the event of any conflict, inconsistency, or
other difference between the terms and provisions of these Rules and
Regulations, as now or hereafter in effect and the terms and provisions of any
lease now or hereafter in effect between Landlord and any tenant in the
Building, Landlord shall have the right to rely on the term or provision in
either such lease or such Rules and Regulations which is most restrictive on
such tenant and most favorable to Landlord.

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