EXHIBIT NUMBER (10)(xviii)(1)
                                                         TO 1996 FORM 10-K
 
                        FIRST AMENDMENT TO OFFICE LEASE
                        -------------------------------

     THIS FIRST AMENDMENT TO OFFICE LEASE ("Amendment") is made as of this 20th
day of October, 1987, by and between AMERICAN NATIONAL BANK AND TRUST COMPANY OF
CHICAGO, not personally but solely as Trustee under Trust Agreement dated July
12, 1984, and known as Trust No. 61523 ("Landlord"), and THE NORTHERN TRUST
COMPANY, an Illinois corporation ("Tenant").

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

     WHEREAS, Landlord and Tenant have entered into that certain Office Lease
dated July 8, 1987 (the "Lease"), pursuant to which Landlord leases to Tenant 
and Tenant leases from Landlord certain Premises (as defined in the Lease) on
floors 3, 4, 5, 6, 7, 8, 9, 10, 13 and 14 of the building commonly known as
Manufacturers Hanover Plaza located at 10 South LaSalle Street, Chicago,
Illinois (the "Building"); and

     WHEREAS, Landlord desires to lease to Tenant and Tenant desires to lease
from Landlord certain additional premises located on floor 11 of the Building
under the terms and conditions hereinafter set forth;

     NOW, THEREFORE, in consideration of the mutual promises contained herein
and other good and valuable consideration, the receipt and sufficiency of which
is hereby acknowledged, Landlord and Tenant hereby agree as follows:

     1.   ADDITIONAL PREMISES.
          -------------------

          A.   11th Floor 5-Year Space.  Landlord leases to Tenant and Tenant
leases from Landlord the additional premises located on floor 11 of the Building
shown cross-hatched on Exhibit A attached hereto and labelled as "Northern Trust
5-Year Space" ("11th Floor 5-Year Space").

          B.   11th Floor 3-Year Space.  Landlord leases to Tenant and Tenant
leases from Landlord the additional premises located on floor 11 of the Building
shown lined on Exhibit A attached hereto and labelled "Northern Trust 3-Year
Space" ("11th Floor 3-Year Space").

          C.   Incorporation of 11th Floor 5-Year Space and 11th Floor 3-Year 
Space.

               (1)  Exhibit A attached hereto is hereby incorporated into the 
     Lease as Exhibit A-1 thereto.

               (2)  After the words "Trust Company" in the 6th to the last line 
     of Paragraph 1.N. of the Lease, the following shall be inserted: "and the 
     space on floor 11

 
     of the Building cross-hatched on Exhibit A-1 attached hereto and identified
     as "Northern Trust 5-Year Space" ("11th Floor 5-Year Space") and the space
     on floor 11 of the Building lined on Exhibit A-1 attached hereto and
     identified as "Northern Trust 3-Year Space" ("11th Floor 3-Year Space")".

               (3)  After the words "Long-Term Space" in the 3rd to the last
     line of Paragraph 1.N. of the Lease, the following shall be inserted: "and
     11th Floor 5-Year Space and 11th Floor 3-Year Space".

     2.   TERM.
          ----

          A.   11th Floor 5-Year Space Term.  With respect to 11th Floor 5-Year 
Space, the Commencement Date of the Term (as defined in the Lease) shall be the 
earlier of (i) March 1, 1988, or (ii) the date Tenant first occupies all or part
of the 11th Floor 5-Year Space for the conduct of business (the "11th Floor 
5-Year Space Commencement Date"). The Expiration Date of the Term (as defined in
the Lease) with respect to 11th Floor 5-Year Space shall be August 31, 1992 (the
"11th Floor 5-Year Space Expiration Date"), unless terminated earlier or
extended as otherwise provided in the Lease or herein. The period commencing on
the 11th Floor 5-Year Space Commencement Date and ending on the 11th Floor 5-
Year Space Expiration Date is hereinafter referred to as the "11th Floor 5-Year
Space Term".

          B.   11th Floor 3-Year Space Term.  With respect to 11th Floor 3-Year 
Space, the Commencement Date of the Term shall be the earlier of (i) March 1, 
1988, or (ii) the date Tenant first occupies all or part of the 11th Floor 3-
Year Space for the conduct of business (the "11th Floor 3-Year Space 
Commencement Date"). The Expiration Date of the Term with respect to 11th Floor 
3-Year Space shall be August 31, 1990 (the "11th Floor 3-Year Space Expiration 
Date"), unless terminated earlier or extended as otherwise provided in the Lease
or herein. The period commencing on the 11th Floor 3-Year Space Commencement 
Date and ending on the 11th Floor 3-Year Space Expiration Date is hereinafter 
referred to as the "11th Floor 3-Year Space Term".

          C.   Confirmation of Term.  At Landlord's request, Tenant shall 
execute a statement setting forth the 11th Floor 5-Year Space Commencement Date 
and the 11th Floor 3-Year Space Commencement Date, determined as provided above,
but no failure by Tenant to do so shall affect the determination of such dates.

          D.   Incorporation of 11th Floor 5-Year Space Term and 11th Floor 3-
Year Space Term.

                                       2

 
          (1)  The following shall be inserted at the end of Paragraph 1.E. of 
     the Lease: "and from the 11th Floor 5-Year Space Commencement Date (as
     hereinafter defined) to and including the 11th Floor 5-Year Space
     Expiration Date (as hereinafter defined) as to 11th Floor 5-Year Space (as
     hereinafter defined) ("11th Floor 5-Year Space Term") and from the 11th
     Floor 3-Year Space Commencement Date (as hereinafter defined) to and
     including the 11th Floor 3-Year Space Expiration Date (as hereinafter
     defined) as to 11th Floor 3-Year Space (as hereinafter defined) ("11th
     Floor 3-Year Space Term")".

          (2)  The following shall be inserted at the end of Paragraph 1.F. of 
     the Lease: ", as to Short-Term Space and Long-Term Space and the earlier of
     (i) March 1, 1988, or (ii) the date Tenant first occupies all or part of
     the 11th Floor 5-Year Space for the conduct of business (the "11th Floor 5-
     Year Space Commencement Date") as to 11th Floor 5-Year Space and the
     earlier of (i) March 1, 1988, or (ii) the date Tenant first occupies all or
     part of the 11th Floor 3-Year Space for the conduct of business (the "11th
     Floor 3-Year Space Commencement Date") as to 11th Floor 3-Year Space".

          (3)  Before the word "and" in line 6 of Paragraph 1.G. of the Lease, 
     the following shall be inserted: "and as to 11th Floor 3-Year Space ("11th
     Floor 3-Year Space Expiration Date")".

          (4)  The following shall be inserted at the end of Paragraph 1.G. of 
     the Lease: "and the last day of the fifth (5th) Lease Year as to 11th Floor
     5-Year Space ("11th Floor 5-Year Space Expiration Date")".

          (5)  Before the words "Commencement Date" in line 6 of Paragraph 2 of 
     the Lease, the word "respective" shall be inserted.

          (6)  After the words "Long-Term Space," in line 9 of paragraph 2 of 
     the Lease, the following shall be inserted: "and on the 11th Floor 5-Year
     Space Expiration Date, as to 11th Floor 5-Year Space, and on the 11th Floor
     3-Year Space Expiration date, as to 11th Floor 3-Year Space".

          (7)  Before the words "the Premises" in line 2 of Paragraph 4.A. of 
     the Lease, the words "each portion of" shall be inserted.

          (8)  Before the word "Commencement" in line 2 of Paragraph 4.A. of the
     Lease, the word "respective" shall be inserted.

                                       3

 
               (9)  Wherever in Paragraph 13 of the Lease the phrase "Short-Term
     Space or Long-Term Space" shall appear the following shall be inserted
     after such phrase: "or 11th Floor 5-Year Space or 11th Floor 3-Year Space".

               (10) Wherever in Paragraph 13 of the Lease the phrase "Short-Term
     Space Term or Long-Term Space Term" shall appear the following shall be
     inserted after such phrase: "or 11th Floor 5-Year Space Term or 11th Floor
     3-Year Space Term".

               (11) At the beginning of line 6 of Paragraph 14 of the Lease, the
     following shall be inserted: "or all or any part of the 11th Floor 5-Year
     Space after the 11th Floor 5-Year Space Expiration Date or all or any part
     of the 11th Floor 3-Year Space after the 11th Floor 3-Year Space
     Expiration Date".

               (12) After the words "Short-Term Space" in line 16 of Paragraph 
     14 of the Lease, the following shall be inserted: ", 11th Floor 5-Year
     Space, 11th Floor 3-Year Space".

               (13) After the words "Expiration Date" in line 7 of Paragraph 19
     of the Lease, the following shall be inserted: ", 11th Floor 5-Year Space
     Expiration Date, 11th Floor 3-Year Space Expiration Date".

     3.   RENTABLE AREA AND TENANT'S PROPORTIONATE SHARE.
          ----------------------------------------------

          A.   Rentable Area.  "Rentable Area of 11th Floor 5-Year Space" shall
mean 4,001 square feet. "Rentable Area of 11th Floor 3-Year Space" shall mean
16,721 square feet.

          B.   Tenant's Proportionate Share. Tenant's Proportionate Share (as 
defined in the Lease) as to 11th Floor 5-Year Space shall be .562%.  Tenant's 
Proportionate Share as to 11th Floor 3-Year Space shall be 2.351%.

          C.   Incorporation of Rentable Area and Tenant's Proportionate Share.

               (1)  Paragraph 1.I. of the Lease is hereby deleted in its 
     entirety and the following shall be substituted therefor:

"I.  Rentable Area of 
      Premises:                                 199,130 square feet (78,051
                                                square feet of Rentable Area of
                                                Short-Term Space, 100,357 square
                                                feet of Rentable Area of Long-
                                                Term Space, 4,001 square feet of
                                                Rentable Area of 11th

                                       4

 
                                                Floor 5-year Space, and 16,721 
                                                square feet of Rentable Area of 
                                                11th Floor 3-Year Space)".

                    (2)  Paragraph 1.L. of the Lease is hereby deleted in its
          entirety and the following shall be substituted therefor:

     "L. Tenant's Proportionate
          Share:                             27.995% (10.973% as to Short-Term 
                                             Space, 14.109% as to Long-Term 
                                             Space, .562% as to 11th Floor 5- 
                                             Year Space and 2.351% as to 11th
                                             Floor 3-Year Space)".

                    (3)  Before the words "shall mean" in line 4 of Paragraph
          7.A(3) of the Lease, the following shall be inserted: "and "Rentable
          Area of 11th Floor 5-Years Space" and "Rentable Area of 11th Floor 3-
          Year Space "."

                    (4)  After the word "Space" in line 8 of Paragraph 7.A(3) of
          the Lease, the following shall be inserted: "and Rentable Area of 11th
          Floor 5-Year Space and Rentable Area of 11th Floor 3-Year Space".

                    (5)  After the words "Long-Term Space" in line 17 of
          Paragraph 7.A(3) of the Lease, the following shall be inserted:
          ",Rentable Area of 11th Floor 5-Year Space, Rentable Area of 11th
          Floor 3-Year Space".

                    (6)  After the Word "Date" in line 6 of Paragraph 7.A(5) of
          the Lease, the following shall be inserted: ", 11th Floor 5-Year Space
          Expiration Date or 11th Floor 3-Year Space Expiration Date".

                    (7)  Before the word "Tenant's" in line 8 of Paragraph
          7.A(5) of the Lease, the following sentence shall be inserted: "Prior
          to the 11th Floor 5-Year Space Commencement Date and the 11th Floor 3-
          Year Space Commencement Date, Tenant's Proportionate Share shall not
          include the portion of Tenant's Proportionate Share attributable to
          11th Floor 5-Year Space or 11th Floor 3-Year Space, respectively".

          4.RENT.
            ----

            A.  Base Rent for 11th Floor 5-Year Space. Annual Base Rent for 11th
     Floor 5-Year Space shall be as follows:

                                       5


 
          Period                                    Annual Base Rent
          ------                                    ----------------

First (1st) Lease Year                       $16.00 per square foot of 
                                             Rentable Area of 11th Floor 5-
                                             Year Space (i.e., $64,016.00).

Second (2nd) Lease Year                      $18.00 per square foot of Rentable 
                                             Area of 11th Floor 5-Year Space 
                                             (i.e., $72,018.00).

Third (3rd) Lease Year                       $20.00 per square foot of Rentable 
                                             Area of 11th Floor 5-Year Space 
                                             (i.e., $80,020.00).

Fourth (4th) Lease Year                      $23.50 per square foot of Rentable 
                                             Area of 11th Floor 5-Year Space 
                                             (i.e., $94,023.50).

Fifth (5th) Lease Year                       $23.50 per square foot of Rentable 
                                             Area of 11th Floor 5-Year Space 
                                             (i.e., $94,023.50).

          B.   Base Rent for 11th Floor 3-Year Space. Annual Base Rent for 11th
Floor 3-Year Space shall be as follows:

          Period                                    Annual Base Rent
          ------                                    ----------------

First (1st) Lease Year                       $16.00 per square foot of 
                                             Rentable Area of 11th Floor 3-
                                             Year Space (i.e., $267,536.00).

Second (2nd) Lease Year                      $18.00 per square foot of Rentable 
                                             Area of 11th Floor 3-Year Space 
                                             (i.e., $300,978.00).

Third (3rd) Lease Year                       $20.00 per square foot of Rentable 
                                             Area of 11th Floor 3-Year Space 
                                             (i.e., $334,420.00).

          C.  Definition of Lease Year. As used in this Amendment, the term
"Lease Year" shall have the same meaning as set forth in the Lease (i.e., each
twelve (12) consecutive calendar month period commencing on September 1 and
ending on August 31).

          D.   Incorporation of Rent.

               (1)  The Annual Base Rent table for 11th Floor 5-Year Space set
          forth in Paragraph 4.A. above shall be incorporated into the Lease as
          Paragraph 1.H(iii). The Annual Base Rent table for 11th Floor 3-Year
          Space set forth in Paragraph 4.B. above shall be incorporated into the
          Lease as Paragraph 1.H(iv).

                                       6


 
               (2)  After the words "Paragraph 6 below)" in line 18 of Paragraph
     3.D. of the Lease, the following shall be inserted: "and 11th Floor 5-Year
     Space Rent (as defined in Paragraph 6 below) and 11th Floor 3-Year Space
     Rent (as defined in Paragraph 6 below)".

               (3)  At the end of the first sentence of Paragraph 6 of the
     Lease, the following shall be inserted: ", as to Short-Term Space and 
     Long-Term Space, and at the annual rate stated in Paragraph 1.H(iii), as to
     11th Floor 5-Year Space, and at the annual rate stated in Paragraph
     1.H(iv), as to 11th Floor 3-Year Space".

               (4)  Before the words "Rent shall be" in line 12 of the second
     paragraph of Paragraph 6 of the Lease, the following sentence shall be
     inserted: "Base Rent pertaining to 11th Floor 5-Year Space, as set forth in
     Paragraph 1.H(iii) above, along with Rent Adjustment and additional rent
     pertaining to 11th Floor 5-Year Space, shall be collectively called "11th
     Floor 5-Year Space Rent" and Base Rent pertaining to 11th Floor 3-Year
     Space, as set forth in Paragraph 1.H(iv) above, along with Rent Adjustment
     and additional rent pertaining to 11th Floor 3-Year Space, shall be
     collectively called "11th Floor 3-Year Space Rent."."

               (5)  After the word "Rent" in line 17 of Paragraph 16.A(3) of the
     Lease, the following shall be inserted: "11th Floor 5-Year Space Rent or
     11th Floor 3-Year Space Rent".

     5.   TENANT ALLOWANCE.  Landlord shall pay as an allowance towards the cost
          ----------------
of the Tenant Improvement Work (as defined in the Workletter Agreement attached 
to the Lease (the "Workletter")) an amount equal to $15.00 per square foot of 
Rentable Area of 11th Floor 5-Year Space and $15.00 per square foot of Rentable 
Area of 11th Floor 3-Year Space, payable in accordance with Paragraph 8 of the
Workletter. Accordingly, the following shall be inserted at the end of Paragraph
1.S. of the Lease: "$15.00 per square foot of Rentable Area of 11th Floor 5-Year
Space and $15.00 per square foot of Rentable Area of 11th Floor 3-Year Space".

     6.   ONE-YEAR OPTIONS TO EXTEND.
          --------------------------

          A.   One-Year Options to Extend. Provided that as of the 11th Floor 
3-Year Space Expiration Date (i.e., August 31, 1990) and at the time each 
option described below is exercised, no Default of Tenant exists under the 
Lease or hereunder, Landlord hereby grants to Tenant the option to extend the 
11th Floor 3-Year Space Term in respect to all (and not less than all) of the 
11th Floor 3-Year Space upon the terms, covenants, conditions and provisions 
contained in the

                                       7

 
Lease and herein (except that (i) Annual Base Rent will be as set forth in the
following sentence, (ii) no additional construction allowance will be paid by
Landlord and (iii) no additional options to extend will be created by the
exercise of any such option to extend), for two (2) separate, successive periods
of one (1) year each, to follow consecutively upon the 11th Floor 3-Year Space
Expiration Date, so that the 11th Floor 3-Year Space Term shall expire on the
Short-Term Space Expiration Date (as defined on the Lease) as extended pursuant
to each of the two (2) respective one (1) year extension options granted under
Paragraph 27.A. of the Lease. The Annual Base Rent for any such period shall be
Twenty-Three Dollars and Fifty Cents ($23.50) per annum per square foot of
Rentable Area of 11th Floor 3-Year Space (i.e., $392,943.50). Tenant's Rent
Adjustment obligation under Paragraph 7 of the Lease shall continue. Each such
option shall be exercisable by Tenant's giving written notice (which shall be
irrevocable) to Landlord of its exercise of the same not less than one (1) year
prior to the expiration date of the then current 11th Floor 3-Year Space Term.
The option to extend for the second one-year extension period shall be
conditioned upon Tenant's having exercised the option to extend the 11th Floor 
3-Year Space Term for the first one-year extension period.

          B.   No Assignment. Tenant shall have no right to assign, transfer, or
otherwise dispose of any of its rights or interests under this Paragraph 6, such
rights being granted solely to The Northern Trust Company; provided, however, 
any successor by merger, consolidation or acquisition of all or substantially 
all of the assets or capital stock of The Northern Trust Company shall be 
entitled to the rights granted to The Northern Trust Company hereunder.

     7.   TEN-YEAR OPTION TO EXTEND.
          -------------------------

          A.   11th Floor 5-Year Space. Provided that as of the 11th Floor 5-
Year Space Expiration Date (i.e., August 31, 1992) and at the time the option
described below is exercised, no Default of Tenant exists under the Lease or
hereunder and provided that Cameron Properties, Inc., has waived its expansion
option with respect to the 11th Floor 5-Year Space or such option has expired,
Landlord hereby grants to Tenant the option to extend the 11th Floor 5-Year
Space Term in respect to all (and not less than all) of the 11th Floor 5-Year
Space upon the terms, covenants, conditions and provisions contained in the
Lease and herein (except that (i) Rent will be as set forth below in this
Paragraph 7.A., (ii) additional construction allowance will be paid by Landlord
as set forth below in this Paragraph 7.A., and (iii) no additional options to
extend will be created by the exercise of such option to extend), for one (1)
period of ten (10) years, to follow consecutively upon the 11th Floor 5-Year
Space Expiration Date, so that the 11th Floor 5-Year Space Term shall expire on
the Long-Term Space

                                       8

 
Expiration Date (as defined in the Lease). The Rent for any Lease Year within 
such extension period shall be calculated on the basis of the prevailing rental 
rate(s) (as defined in Paragraph 27.B(ii) of the Lease), but in no event shall 
the Annual Base Rent for such extension term be less than the Annual Base Rent 
for 11th Floor 5-Year Space, as adjusted, for the fifth (5th) Lease Year. Such 
option shall be exercisable by Tenant's giving written notice (which shall be 
irrevocable) to Landlord of its exercise of the same not less than one (1) year 
prior to the 11th Floor 5-Year Space Expiration Date. If Tenant so exercises 
said option, Landlord shall pay as additional allowance toward the cost of 
Tenant Improvement Work for the 11th Floor 5-Year Space an amount equal to 
$15.00 per square foot of Rentable Area of 11th Floor 5-Year Space, payable in 
accordance with Paragraph 8 of the Workletter.

          B.   11th Floor 3-Year Space. Provided that Tenant has previously
exercised both one (1) year extension options granted under Paragraph 6 above
and that as of the 11th Floor 3-Year Space Expiration Date, as extended (i.e.,
August 31, 1992), and at the time the option described below is exercised, no
Default of Tenant exists under the Lease or hereunder, Landlord hereby grants to
Tenant the option to extend the 11th Floor 3-Year Space Term in respect to al
(and not less than all) of the 11th Floor 3-Year Space upon the terms,
covenants, conditions and provisions contained in the Lease and herein (except
that (i) Rent will be as set forth below in this Paragraph 7.B., (ii) additional
construction allowance will be paid by Landlord as set forth below in this
Paragraph 7.B., and (iii) no additional options to extend will be created by the
exercise of such option to extend), for one (1) period of ten (10) years, to
follow consecutively upon the 11th Floor 3-Year Space Expiration Date as
extended under Paragraph 6 above, so that the 11th Floor 3- Year Space Term
shall expire on the Long-Term Space Expiration Date. The Rent for any Lease Year
within such extension period shall be calculated on the basis of the prevailing
rental rate(s) (as defined in Paragraph 27.B(ii) of the Lease), but in no event
shall the Annual Base Rent for such extension term be less than the Annual Base
Rent for 11th Floor 3-Year Space, as adjusted, for the fifth (5th) Lease Year.
Such option shall be exercisable by Tenant's giving written notice (which shall
be irrevocable) to Landlord of its exercise of the same not less than one (1)
year prior to the 11th Floor 3-Year Space Expiration Date, as extended under
Paragraph 6 above. If Tenant so exercises said option, Landlord shall pay as
additional allowance toward the cost of Tenant Improvement Work for 11th Floor
3-Year Space an amount equal to $15.00 per square foot of Rentable Area of 11th
Floor 3-Year Space, payable in accordance with Paragraph 8 of the Workletter.

          C.   No Assignment. Tenant shall have no right to assign, transfer or 
otherwise dispose of any of its rights or interests under this Paragraph 7, such
rights being granted

                                       9

 
solely to The Northern Trust Company; provided, however, any successor by 
merger, consolidation or acquisition of all or substantially all of the assets 
or capital stock of The Northern Trust Company shall be entitled to the rights 
granted to The Northern Trust Company hereunder.

     8.   LONG-TERM OPTIONS TO EXTEND.
          ---------------------------

          A.   Long-Term Options. Provided that Tenant has previously exercised 
both of the ten (10) year extension options granted under Paragraph 7 above, and
that as of the 11th Floor 5-Year Space Expiration Date, as extended (i.e., 
August 31, 2002), and the 11th Floor 3-Year Space Expiration Date, as extended 
(i.e., August 31, 2002), and at the time that each option described below is 
exercised, no Default of Tenant exists hereunder, Landlord hereby grants to 
Tenant the option to extend the 11th Floor 5-Year Space Term and the 11th Floor
3-Year Space Term in respect to all (and not less than all) of the 11th Floor 
5-Year Space and 11th Floor 3-Year Space upon the terms, covenants, conditions 
and provisions contained in the Lease and herein (except that (i) Rent will be 
as set forth in the following sentence, (ii) no additional construction 
allowance will be paid by Landlord and (iii) no additional options to extend 
will be created by the exercise of any such option to extend, for two (2) 
separate, successive periods of ten (10) years each, to follow consecutively
upon the 11th Floor 5-Year Space Expiration Date and 11th Floor 3-year Space
Expiration Date, respectively, so that the 11th Floor 5-Year Space Term and the
11th Floor 3-Year Space Term, respectively, shall expire on the Long-Term Space
Expiration Date as extended pursuant to each of the two (2) respective ten (10)
year extension options granted under Paragraph 27.B. of the Lease. The Rent for
any Lease Year within such extension period shall be calculated on the basis of
the prevailing rental rate(s) (as defined in Paragraph 27.B(ii) of the Lease),
but in no event shall the Annual Base Rent for either extension term be less
than the Annual Base Rent for the 11th Floor 5-Year Space and 11th Floor 3-Year
Space, respectively, as adjusted, for the fifteenth (15th) Lease Year (in the
case of the first extension option) or the last Lease Year of the first ten (10)
year extension term granted under this Paragraph 8.A. (in the case of the second
extension term). Each such option shall be exercisable by Tenant's giving
written notice (which shall be irrevocable) to Landlord of its exercise of same
not less than one (1) year prior to the expiration date of the then current 11th
Floor 5-Year Space Term and 11th Floor 3-Year Space Term. The option to extend
for the second ten-year extension period granted under this Paragraph 8.A. shall
be conditioned upon Tenant's having exercised the option to extend the 11th
Floor 5-Year Space Term and 11th Floor 3-Year Space Term for the first ten-year
extension period.

                                      10

 
          B.   No Assignment. Tenant shall have no right to assign, transfer or 
otherwise dispose of any of its rights or interests under this Paragraph 8, such
rights being granted solely to the Northern Trust Company; provided, however, 
any successor by merger, consolidation or acquisition of all or substantially 
all of the assets or capital stock of The Northern Trust Company shall be 
entitled to the rights granted to The Northern Trust Company hereunder.

     9.   EXERCISE OF SHORT-TERM SPACE OPTIONS TO EXTEND WITH RESPECT TO FLOOR 
          --------------------------------------------------------------------
14.  Notwithstanding anything to the contrary contained in the Lease, Tenant
- --
hereby exercises its right to extend the Short-Term Space Term with respect to 
the Short-Term Space located on floor 14 of the Building for both of the one (1)
year extension periods granted under Paragraph 27.A. of the Lease. Such 
extension periods shall be under the terms, covenants and conditions set forth 
in Paragraph 27.A. Nothing contained in this Paragraph 10 shall be construed as 
modifying or altering Paragraph 27.A. in any way with respect to the balance of 
the Short-Term Space.

     10.  PRIORITY OF EXERCISE OF SHORT-TERM SPACE OPTION TO EXTEND.
          ---------------------------------------------------------

          A.   Amendment of Short-Term Space Options. Landlord hereby grants to 
Tenant the right to exercise the options to extend the Short-Term Space Term 
granted under Paragraph 27.A. of the Lease on a floor-by-floor basis (i.e., 
Tenant may exercise its option to extend with respect to all (but not less than 
all) of the Short-Term Space located on one or more floors of the Building).

          B.   Priority. Tenant hereby agrees to exercise its Short-Term Space 
options to extend granted under Paragraph 27.A. of the Lease, as amended by 
Paragraph 10.A. above, in the following order of priority: (a) Tenant shall 
exercise its options to extend with respect to Short-Term Space located on 
floors 3, 9 or 11 of the Building prior to exercising its options to extend with
respect to Short-Term Space located on floors 10 or 13 of the Building, and (b) 
Tenant shall exercise its options to extend with respect to Short-Term Space
located on floor 10 of the Building prior to its exercising its option to
extend with respect to Short-Term Space located on floor 13 of the Building.

     11.  BROKER.
          ------

          A.   Tenant Representation. Tenant represents to Landlord and the 
Beneficiary that except for Scribcor, Inc., Tenant has not dealt with any real 
estate broker, sales person or finder in connection with this Amendment and no
other person initiated or participated in the negotiation of this

                                      11

 
Amendment or showed the 11th Floor 5-Year Space or 11th Floor 3-Year Space to 
Tenant. Tenant agrees to indemnify, defend and hold harmless Landlord, the 
Beneficiary, the Manager and their respective officers, partners and employees, 
from and against any and all claims, demands, liabilities, actions, damages, 
costs and expenses (including attorneys' fees) for brokerage commissions or fees
arising out of a breach of such representation.

          B.   Landlord Representation. Landlord represents to Tenant that 
except for Scribor, Inc., Landlord has not dealt with any real estate broker, 
sales person or finder in connection with this Amendment, and no other person 
initiated or participated in the negotiation of this Amendment. Landlord agrees 
to indemnify, defend and hold harmless Tenant and its officers and employees 
from and against any and all claims, demands, liabilities, actions, damages, 
costs and expenses (including attorneys' fees) for brokerage commissions or fees
arising out of a breach of such representation.

          C.   Tenant Payment of Brokerage Fees. Scribor, Inc., has acted as 
consultant to Tenant in connection with this Amendment and Tenant shall be 
solely responsible for the payment of any and all fees, compensation and 
expenses due Scribor, Inc. Tenant agrees to indemnify, defend and hold harmless 
Landlord, the Beneficiary, the Manager and their respective officers, partners 
and employees from and against any and all claims, demands, liabilities, 
actions, damages, costs and expenses (including attorneys' fees) which may 
arise out of the failure of Tenant to pay such fees, compensations and expenses 
to Scribor, Inc.

     12.  AMENDMENTS TO WORKLETTER AGREEMENT.
          ----------------------------------

          A.   After the words "Refusal Space" in line 9 of Paragraph 2(a) 
on page C-6 of the Workletter, the following shall be inserted: "(iv) after 
October 20, 1987, with respect to additional Tenant Improvement Work in the 11th
Floor 5-Year Space and the 11th Floor 3-Year Space".

          B.   After the words "Refusal Space" in line 9 of Paragraph 2(b) on 
page C-7 of the Workletter, the following shall be inserted: "(iv) after October
20, 1987, with respect to additional Tenant Improvement Work in the 11th Floor 
5-Year Space and the 11th Floor 3-Year Space".

     13.  FULL FORCE AND EFFECT.  Except as specifically provided in this 
          ---------------------
Amendment, the Lease shall continue in full force and effect, and the same is 
hereby ratified nd confirmed as amended hereby. No waiver by Landlord of any 
Default by Tenant under the Lease, whether past, current or future, shall be 
implied or construed by any provision herein or because of Landlord's failure to
act with respect thereto

                                      12

 
     14.  EXCULPATION.   This Amendment is executed by American National Bank 
          -----------
and Trust Company of Chicago, not personally but as Trustee as aforesaid, in the
exercise of the power and authority conferred upon and vested in it as such 
Trustee, and under the express direction of the beneficiaries of a certain Trust
Agreement dated July 12, 1984, and known as Trust Number 61523 at American 
National Bank and Trust Company of Chicago, to all provisions of which Trust 
Agreement this Amendment is expressly made subject. It is expressly understood 
and agreed that nothing contained in this Amendment shall be construed as 
creating any liability whatsoever against said Trustee personally, and in
particular without limiting the generality of the foregoing, there shall be no
personal liability to pay any indebtedness accruing hereunder or to perform any
covenant, either express or implied, contained herein, or to keep, preserve or 
sequester any property of said Trust, and that all personal liability of said
Trustee of every sort, if any, is hereby expressly waived by Tenant, and by
every person now or hereafter claiming any right or security hereunder; and that
so far as the said Trustee is concerned the owner of any indebtedness or
liability accruing hereunder shall look solely to the Premises for the payment
of same.

     IN WITNESS WHEREOF, Landlord and Tenant have executed this Amendment as of 
the day and year first above written.

LANDLORD:                          TENANT:

AMERICAN NATIONAL BANK AND         THE NORTHERN TRUST COMPANY
 TRUST COMPANY OF CHICAGO,
not personally but solely
as Trustee under Trust No.         By:   Stephen Kardel  
                                      ------------------------------
61523                                  Title: Vice President

By: A.M. Lutkus 
    -------------------------
    Title: Authorized Officer

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                                   EXHIBIT A





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