<PAGE>
                                                                    EXHIBIT 10.6

                              ASSIGNMENT AGREEMENT

    THIS ASSIGNMENT AGREEMENT made as of the 31th day of BOSTON (USA), INC., a
Delaware corporation, having an address at 277 Park Avenue, New York, New York
10172 (successor in interest to Donaldson Lufkin & Jenrette, Inc; "ASSIGNOR"),
and THE CHASE MANHATTAN BANK, a New York banking corporation having an address
at Two Chase Manhattan Plaza, New York, New York 10017 ("ASSIGNEE").

                                   BACKGROUND

    WHEREAS, Assignor is the (i) tenant under that certain lease more
particularly described on "Exhibit A attached hereto and made a part hereof (as
so amended, the "CSFB LEASE") between 277 Park Avenue, LLC (as
successor-in-interest to Stanley Stahl D/B/A Stahl Park Avenue Co.; "LANDLORD"),
as landlord, and Assignor, as tenant, of certain premises located at 277 Park
Avenue, New York, New York (the "BUILDING"), which premises are more
particularly described in the Lease (the "CSFB LEASED PREMISES"), and
(ii) current holder of the leasehold interest under that certain Lease, dated as
of August 15, 1986, by and between Landlord and The Mitsui Bank, Ltd.
(predecessor-in-interest to The Sakura Bank, Ltd.; "SAKURA"), as amended
pursuant to that certain Amendment of Lease, dated as December 27, 1989, by and
between Landlord and Sakura, as further amended pursuant to that certain Second
Amendment of Lease, dated as of December 28, 1992, by and between Landlord and
Sakura, as further amended pursuant to that certain Third Amendment of Lease,
dated as of March 8,1995, by and between Landlord and Sakura (the "SAKURA
LEASE"; collectively, the CSFB Lease and the Sakura Lease are hereinafter the
"Lease") leasing certain premises located at the Building, which premises are
more particularly described in the Lease (the "SAKURA LEASED PREMISES";
collectively, the CSFB Leased Premises and the Sakura Leased Premises, are
hereinafter the "LEASED PREMISES").

    WHEREAS, Assignor desires to assign and Assignee desires to acquire all of
Assignor's right, title and interest in the Lease pursuant to the terms more
particularly described herein.

    NOW, THEREFORE, in consideration of the mutual covenants set forth in this
Assignment, and other good and valuable consideration, the receipt and
sufficiency of which are hereby acknowledged by the patties to this Assignment,
the parties agree as follows:

    1.  ASSIGNMENT.  Assignor for the sum of $360,500,000 (the "PAYMENT"),
hereby assigns to Assignee, as of the date upon which this Assignment is
released from escrow (the "EFFECTIVE DATE") pursuant to that certain Escrow
Agreement, dated as of the date hereof, by and among, Assignor, Assignee and
Skadden, Arps, Slate, Meagher & Flom LLP, as escrow agent, all of Assignor's
right, title and interest in, to and under the Lease and the leasehold estate
created pursuant to the Lease (excluding therefrom that certain (i) Amended and
Restated Lease Agreement (Project Property), dated August 1, 1995, by and
between New York City Industrial Development Agency ("IDA") and Assignor, as
successor in interest to the original lessee thereunder, and (ii) Amended and
Restated Company Lease Agreement (Facility Realty), dated August 1, 1995, by and
between IDA,and Assignor, as successor in interest to the original lessee
thereunder (collectively,,the "IDA SUBLEASE"), provided, however, that the IDA
Subleases shall become subject and subordinate to the Sublease (as hereinafter
defined)), and including without limitation all rights, powers and privileges of
Assignor as the tenant under the Lease, except for Assignor's right to any
overpayment of additional rent and any other sums reimbursable under the Lease
in respect of any time period prior to the Effective Date. Assignor and Assignee
agree that a portion of the Payment in an amount equal to (i) $125,000,000 shall
be allocable to leasehold improvements, and (ii) $40,000,000 shall be allocable
to personal property. The payment of the Payment shall satisfy Assignee's
obligation to make payment under the Bill of Sale (as hereinafter defined)
executed in connection herewith. Assignee shall pay the Payment to Assignor on
the Effective Date (the "PAYMENT DATE") by wire transfer of immediately
available federal funds wired to Citibank, ABA#021000089, A/C CSFB written
notice of the date of delivery of the Initial Space, Second Space, any Partial
Block (the "PARTIAL BLOCK DELIVERY DATE") or of the Remainder Space in the event
of such delivery shall be on a date other than the scheduled delivery date set
forth on EXHIBIT B. From and after the Effective Date, Assignee shall sublease
to Assignor, pursuant to the
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sublease agreement attached hereto as EXHIBIT C (the "SUBLEASE"), all portions
of the Leased Premises which have not been delivered to Assignee on the
Effective Date.

    3.  ASSUMPTION.  Except as otherwise provided herein, from and after the
Effective Date, Assignee assumes all of the obligations of Assignor under the
Lease, and agrees to be personally bound by all of the terms, covenants and
conditions of the Lease, and to perform all of the duties and obligations of
Assignor under the Lease, in each case to the extent they arise from events
occurring on and after the Effective Date. As between Assignor and Assignee,
Assignee is not assuming the obligation to pay rent, additional rent and any
other sums payable under the Lease with respect to any time period prior to the
Effective Date.

    4.  ADJUSTMENTS.

    (a) If the Effective Date is other than the first day of a calendar month,
       Assignor shall pay the rent and additional rent due for the month in
       which the Effective Date falls. All rent and additional rent and other
       sums and charges payable in accordance with the provisions of the Lease
       will be apportioned between Assignor and Assignee as of the Effective
       Date so that Assignor shall be obligated for such amounts prior to the
       Effective Date and Assignee shall be obligated for such amounts for the
       period commencing on the Effective Date through and including the last
       day of such month,

    (b) In the event Assignor delivers any part of the Leased Premises prior to
       the scheduled delivery dates set forth on EXHIBIT B ("EARLY DELIVERY
       SPACE"), then the Payment shall be adjusted (the "NEW PAYMENT") pursuant
       to the same calculations utilized to determine the original Payment and
       any such adjustment shall be payable by Assignee within thirty (30) days
       after the Delivery Date (as hereinafter defined) of the applicable Early
       Delivery Space. Accordingly, the Payment shall be increased on a per diem
       basis for each day, from the actual delivery of such space to the
       scheduled delivery date, in an amount equal to the product of (i) the
       rentable square feet of each such Early Delivery Space, and (ii) the
       difference between (x) $0.22 (i.e. $78.50 per annum stated on a per diem
       basis), and (y) the Existing Rent (as hereinafter defined) for Early
       Delivery Space payable under the Lease stated on a per diem basis.
       "EXISTING RENT" shall mean the actual rental rate; (including escalations
       applicable thereto) for the particular Early Delivery Space then being
       delivered to Assignee.

    (c) In the event that at any time after the Effective Date, the rent,
       additional rent, taxes, or other components utilized in the calculation
       of the Payment shall be increased or decreased, whether by adjustment
       pursuant to the provisions of the Lease or by reason of tax certiorari
       proceedings or other similar process, then the Payment shall be adjusted
       accordingly, and any such adjustment shall be payable within thirty
       (30) days after receipt of a statement from the other party setting forth
       the calculation thereof.

    (d) (i) In the event Assignor delivers any part of the Initial Space after
       the scheduled delivery dates set forth on EXHIBIT B (any such portion of
       the Initial Space being hereinafter referred to as the "INITIAL LATE
       DELIVERY SPACE"), then the Payment shall be adjusted (the "INITIAL SPACE
       LATE PAYMENT") pursuant to the same calculations utilized to determine
       the original Payment, except as described below. Accordingly, the Payment
       shall be reduced on a per diem basis for each day following the scheduled
       delivery date for such Initial Late Delivery Space to the earlier to
       occur of (u) the actual delivery date of such space and (v) May 30, 2001,
       in an amount equal to the product of (w) the rentable square feet of such
       Initial Late Delivery Space and (x) the difference between (1) $0.22
       (i.e. $78.50 per annum stated on a per diem basis), and (2) the Existing
       Rent for such Initial Late Delivery Space, stated on a per diem basis;
       provided that if the actual delivery date shall occur after May 30, 2001,
       then the Payment shall be reduced thereafter on a per diem basis for each
       day from May 31, 2001 to the actual delivery date of such,space, in an
       amount equal to the product of (y) the rentable square feet of such
       Initial Late Delivery Space, and (z) the difference between (1) $0.44
       (i.e, $157.00 per annum stated on a per diem basis), and (2) the Existing
       Rent for such Initial Late Delivery Space, stared on a per diem basis.
<PAGE>
    (ii) In the event Assignor delivers any part of the (i) Second Space or the
         Remainder Space after the scheduled delivery dates set forth on
         Exhibit E (any such portion of the Second Space or the Remainder Space
         being hereinafter referred to as the "Remainder Late Delivery Space"),
         then the Payment shall be adjusted (the a "Remainder Space Late
         Payment") pursuant to the same calculations utilized to determine the
         original Payment, except as described below. Accordingly, the Payment
         shall be reduced on a per diem basis for each day following the
         scheduled delivery date for such Remainder Late Delivery Space to the
         earlier to occur, of (u) the actual delivery date of such space and
         (v) July 30, 2002, in an amount equal to the product of (w) the
         rentable square feet of such Remainder Late Delivery Space, and
         (x) the DIFFERENCE BETWEEN (1) $0.22 (i.e. $78.50 per annum stated on a
         per diem basis), and (2) the Existing Rent for such Remainder Late
         Delivery Space, stated on a per diem basis; provided that if the actual
         delivery date shall occur after July 30, 2002, then the Payment shall
         be reduced thereafter on a per diem basis for each day from July 31,
         2002 to the actual delivery date of such space, in an amount equal to
         the product of (y) the rentable square feet of such Remainder Late
         Delivery Space and (z) the difference between (1) $0,44 (i.e. $157.00
         per annum stated on a per diem basis), and (2) the Existing Rent for
         such Initial Late Delivery Space, stated on a per diem basis,

   (iii) Any Initial Space Late Payment and Remainder Late Space Payment shall
         be payable by Assignor within thirty (30) days after receipt of
         Assignee's statement setting forth the calculation thereof. Any such
         payments by Assignor shall not modify or reduce Sublessee's obligation
         to pay all rent which becomes due and payable under THE SUBLEASE during
         the term thereof or any period during which Sublessee holds over after
         the expiration of the Term.

    (iv) In the event The Sumitomo Bank, Ltd. ("Sumitomo") does not exercise its
         option with respect to a portion of the fourth (4'h) floor, then the
         Payment shall be adjusted (the "Sumitomo Adjustment"), by increasing
         the Payment by an amount equal to Eight Million Six Hundred Forty Two
         Thousand Dollars ($8,642,000), which Sumitomo Adjustment shall be
         payable by Assignee to Assignor, on the earlier to occur of (i) thirty
         (30) days after notification by Sumitomo that it is declining to
         exercise its option with respect thereto, and (ii) July 15, 2001.

    (v) Assignee shall receive the benefit of the assignment of the 39th and
        40th floors of the Building, pursuant to that certain Letter Agreement,
        dated as of January 24, 2001 (the "January 2001 Letter Agreement"), by
        and between Landlord and Assignor, The terms and provisions governing
        the assignment of such space shall be separate and apart from the terms
        and provisions set forth herein and are more particularly set forth in
        the January 2001 Letter Agreement. Accordingly, the provisions of this
        Section 4 shall not-apply to the delivery of such space.

    5.  ADDITIONAL RENT.  Assignor and Assignee each acknowledge and agree that
Assignee shall, at its sole cost and expense, be responsible for verifying the
Operating Expenses, electricity charges and Real Estate Taxes (collectively,
such items are hereinafter referred to as the "Additional Rent") for the
calendar years 2000, 2001 and 2002 pursuant to Sections 11 and 12 of the Lease,
attributable to that portion of the Leased Premises delivered to Assignee during
the calendar years 2001 and 2002, respectively. Notwithstanding the foregoing,
Assignee agrees to (a) perform its review of such Additional Rent for such
calendar years in good faith, (b) share with Assignor any information obtained
by Assignee as a result of such review, (c) provide Assignor with copies of all
documents and correspondence between Assignee and Landlord with respect to such
Additional Rent, and (d) resolve and/or settle any dispute regarding such
Additional Rent in a commercially reasonable manner consistent with the
resolution of any dispute concerning Additional Rent attributable to other space
leased by Assignee in the Building, except for such differences arising from
different rights and differing expenses and charges under the Lease and the
lease for other space leased by Assignee in the Building respectively. Assignor
shall cooperate with Assignee in connection with Assignee's review of Additional
Rent statements, including, without limitation, providing Assignee with access
to Assignor's books and records with respect to Additional Rent under the Lease.
Assignee shall, within fifteen (15) business days after receipt of any refund
from Landlord, return to Assignor the (i) the full amount of any refunds
obtained from Landlord with respect to Additional Rent which are attributable to
the Leased Premises for the calendar year 2000, and (ii) proportionate amount of
any refunds obtained from Landlord with respect to Additional Rent which are
attributable to that portion
<PAGE>
of the Leased Premises for the portion of calendar years 2001 and 2002 which
occurs prior to the date of delivery to Assignee of possession of the applicable
portion of the Leased Premises in accordance with the terms of this Assignment
(the "Delivery Date"). Notwithstanding the foregoing, Assignee shall be entitled
to deduct from any refund received for such calendar years the actual reasonable
costs incurred by Assignee in connection with the verification of such
Additional Rent. Upon Assignor's request, Assignee shall provide Assignor with
bills, receipts or other reasonable documentation evidencing such costs.
Notwithstanding the foregoing, Assignee shall deliver to Assignor, promptly
after receipt of the same from Landlord, copies of all statements relating to
Additional Rent (x) with respect to any or all of the Leased Premises, for the
period through the end of calendar year 2001 and the tax year 2001, 2002, or
(y) with respect to any portion of the Leased Premises for which the Delivery
Date occurs after December 31, 2001, for the period prior to such Delivery Date.
If Assignor disputes any items on such statements relating to Additional Rent in
respect of the periods set forth in (x) and (y) above, Assignee shall cooperate
with Assignor and shall in good faith exercise such rights as it has to dispute
such items in accordance with the provisions of the Lease, at Assignor's sole
cost and expense (provided, however, that if any such dispute relates to a
period during which the parties each occupied the applicable portion of the
Leased Premises, then the parties shall share the costs and expenses
proportionately). Assignor shall have the right to have a representative present
at all meetings and discussions with the Landlord which relate to any dispute
regarding such Additional Rent.

    6.  REPRESENTATIONS.

(a) Assignor represents and warrants to Assign that:

       (i)A true, correct and complete copy of the Lease, excluding Exhibit U
thereto, but including all amendments, letter agreements, consents, and
non-disturbance agreements are attached as "Exhibit A to this Assignment and
there are no other agreements or understandings, oral or otherwise, that would
be binding on Assignee after the Effective Date.'

    (ii) The Lease is in full force and effect and has not been modified or
         amended except as described above.

   (iii) Assignor has received no notices, written or oral, alleging any default
         by Assignor under the Lease, and no event has occurred which, with the
         passage of time or the giving of notice or both, would constitute a
         default by Assignor under the Lease.

    (iv) Assignor has given no notices, written or oral, alleging any default by
         the Landlord under the Lease; and no event has occurred which, with the
         passage of time or the giving of notice of both would constitute a
         default by the Landlord under the Lease.

    (v) There are no defaults by Assignor and to the best of Assignor's
        knowledge there are no defaults by Landlord under the Lease, and to the
        best of Assignor's knowledge, no event has occurred which, with the
        passage of time or the giving of notice or both, would constitute a
        default by Assignor or Landlord under the Lease.

    (vi) There are no suits, claims, actions, litigation or governmental
         proceedings pending, or to the best of Assignor's knowledge threatened,
         against or relating to the Leased Premises or Assignor which would
         reasonably be expected to adversely affect Assignor's ability to
         effectuate the transaction contemplated hereby or Assignee's ability to
         obtain and have the benefit of Tenant's rights under the Lease.

   (vii) The execution and delivery of this Assignment by Assignor has been duly
         authorized and once executed and delivered, this Assignment shall be
         binding against Assignor and shall be enforceable in accordance with
         its terms.

  (viii) No consent is required to authorize and permit the assignment of the
         Tease to Assignee,

    (ix) The Leased Premises are comprised of the premises as set forth on
         Exhibit attached hereto and made a part hereof.
<PAGE>
    (x) To the best of Assignor's knowledge, the Building systems, including but
        not limited to, UPS systems, generators, fuel tanks and HVAC systems
        (collectively, such systems are hereinafter referred to as the
        "Dedicated Systems"), at the Leased Premises are in good working order
        and condition.

    (xi) Assignor shall assign, to the extent possible pursuant to the terms of
         the same, all warranties and service contracts relating to the Leased
         Premises.

   (xii) The IDA Documents referenced in the Lease and in Exhibit U to the Lease
         and the PILOT Agreement entered into in connection therewith, will not
         diminish Assignee's rights or increase Assignee's obligations, except
         to a de minimus extent, with respect to the Leased Premises or the
         Lease in any respect.

  (xiii) Except as indicated on Exhibit attached hereto, Assignor has no rights
         or options to occupy space in the Building other than as set forth in
         the Lease.

   (xiv) The Landlord Estoppel Certificate attached hereto as s Exhibit G is
         true and correct.

   (xv) To the best of Assignor's knowledge, the fuel tank has been operated and
        maintained in compliance with all applicable laws.

   (xvi) Assignor shall not cause a default under the lease assigned to Assignor
         by Sakura (with RESPECT to premises located on the 31th, 45th and 46th
         floors) that results in a termination of such lease.

    (b) Assignee represents and warrants to Assignor that

    (i) the execution and delivery of this Assignment by Assignee has been duly
        authorized and once executed and delivered, this Assignment shall be
        binding against Assignee and shall be enforceable in accordance with its
        terms.

    (ii) As of the dare hereof. Assignee has no knowledge (without the
       opportunity to inspect base building systems outside the Leased Premises)
       of any defaults by Assignor under the Lease, nor of any defects or
       non-compliance issues with respect to the Leased Premises.

    The representations and warranties of Assignor and Assignee under this
Assignment shall be true and correct both on the date of this Assignment and on
the Effective Date as though made by Assignor or Assignee respectively both on
the date hereof and on each Effective Date and shall survive the Effective Date
for a period of three (3) years from the last Delivery Date, provided, however
that representations or warranties above which are contained in the Landlord
Estoppel Certificate shall not survive beyond the date of the delivery by
Landlord of such Landlord Estoppel Certificate, pursuant to the provisions of
Section 16(j) hereof.

    7.  INDEMNITY.  (a) To the extent not expressly prohibited by law, Assignor
agrees to hold Assignee and its successors and assigns, if any, and their
respective officers, directors, agents, servants and employees harmless and to
indemnify each of them, against claims, liabilities, losses, damages, costs and
expenses, including reasonable attorneys' fees that relate to (A) facts or
circumstances arising prior to the last Delivery Date, including, without
limitation, for injuries to all persons and damage to, or theft,
misappropriation or loss of property occurring in or about the Leased Premises
arising from Assignor's occupancy of the Leased Premises or the conduct of its
business or from any activity work or thing done permitted or suffered by
Assignor in or about the Leased Premises (other than that which is performed by
or on behalf of Assignee) or from any breach or default on the part of Assignor
in the performance of any covenant or agreement on the part of Assignor to be
performed pursuant to the terms of this Assignment or the Lease or due to any
other act or omission (where there is a duty to act) of Assignor, its agents,
contractors, invitees, licensees or employees but only to the extent of
Assignee's liability if any in excess of such amounts if any paid to Assignee
under insurance covering such claims or liabilities. Assignor's obligation to
indemnify Assignee hereunder shall include the duty to defend against any claims
asserted by reason of any such claims of liabilities " and to any judgments
settlements, costs, fees and expenses including attorneys fees reasonably
incurred in connection therewith. The foregoing indemnity shall not include
liability for consequential or punitive damages. The provisions of this Section
shall survive the
<PAGE>
Effective Date. Notwithstanding the foregoing, Assignor's indemnity with respect
to a breach of Assignor's representations and warranties shall survive in
accordance with the provisions of Section 6.

    (b) To the extent not expressly prohibited by law, Assignee agrees TO hold
       Assignor and its successors and assigns, if any, and their respective
       officers, directors, agents, servants and employees harmless and to
       indemnify each of them, that relate to facts or circumstances arising
       from and after the Effective Date, against claims, liabilities, losses,
       damages, costs and expenses including reasonable attorneys' fees
       including, without limitation, for injuries to all persons and damage to,
       or theft, misappropriation or loss of property occurring in or about the
       Leased Premises arising from Assignee's occupancy of the Leased premises
       or the conduct of its business or from any activity work or thing done
       permitted or suffered by Assignee in or about the Leased Premises or from
       any breach or default on the part of Assignee in the performance of any
       covenant or agreement on the part of Assignee to be performed pursuant to
       the terms of this Assignment or the Lease or due to any other act or
       omission (where there is a duty to act) of Assignee, its agents,
       contractors, invitees, licensees or employees but only to the extent of
       Assignor's liability if any in excess of such amounts if any paid to
       Assignor under insurance covering such claims or liabilities.
       Notwithstanding the foregoing, Assignee shall not be obligated to
       indemnify Assignor with respect to any claim or liability arising out of
       or relating to Assignor's interest under the Sublease and Assignor's
       possession of the Leased Premises after the Effective Date. Assignee's
       obligation to indemnify Assignor hereunder shall include the duty to
       defend against any claims asserted by reason of any such claims or
       liabilities and to any judgments settlements, costs, fees and expenses
       including attorney's fees reasonably incurred in connection therewith.
       The foregoing indemnity shall not include liability for consequential or
       punitive damages, The provisions of this Section 7(b) shall survive the
       Effective Date.

    8.  TRANSFER AND OTHER TAXES.  Within fifteen (15) days after the Effective
Date, Assignor and Assignee are completing and executing the New York State
Combined Real Estate Transfer Tax Return and Credit Line Mortgage Certificate
(TP-584) and a New York City Real Property Transfer Tax Return relating to the
Assignment of the Lease. Assignor shall file the same with the appropriate
governmental departments and shall pay all transfer taxes due, if any and hereby
indemnifies and holds Assignee harmless from any liability, cost or expense
arising from or relating to the payment of transfer taxes in connection with
this Assignment. Assignee agrees to sign any supplemental transfer tax forms
required to be completed and filed, from time to time, in connection with any
adjustments to the Payment. The Indemnity contained in this SECTION 8 shall
survive the Effective Date.

    9.  BROKERS.  Each of Assignor and Assignee represents that no broker other
than CSFB Realty Corp, ("ASSIGNOR'S BROKER") and Insignia/ESG, Company, Inc.
("ASSIGNEE'S BROKER") brought about this Assignment. Assignee represents and
warrants to Assignor that Assignee has had no dealings of any kind with any
other broker or any other party in connection with the Leased Premises and
hereby indemnifies and holds Assignor harmless from any claim of Assignee's
Broker or any other broker or party for any commission or compensation in
connection with the assignment of the Lease or the Sublease arising and based
upon any dealing or negotiation by such broker or other party with Assignee.
Assignor represents and warrants to Assignee that Assignor has had no dealings
of any kind with any other broker or any other party in connection with the
Leased Premises and hereby indemnifies and holds Assignee harmless from any
claim of Assignor's Broker or any other broker or party for any commission or
compensation in connection with the assignment of the Lease or the Sublease
arising and based upon any dealing or negotiation by such broker or other party
with Assignor. Assignee shall pay Assignor's Broker and Assignee's Broker their
respective commissions pursuant to the provisions of a separate agreement. The
provisions of this Section shall survive the expiration or termination of this
Assignment, and are not intended to run to the benefit of the aforesaid brokers.

    10.  "AEIS" (a) Assignee represents that Assignee has made an examination
and inspection of the Leased Premises and any leasehold improvements contained
therein, Assignee agrees that, except as expressly provided herein, Assignee
enters into this Assignment without any representations or warranties by
Assignor, its agents, representatives, employees, servants or any other person
as to the condition of the Leased Premises or as to their fitness for the use or
purpose intended by Assignee. Assignee agrees to
<PAGE>
accept the Leased Premises "as is" and in "broom clean" condition as of the
Effective Date without requiring any alterations, improvements, repairs or
decorations to be made by Assignor or at Assignor's expense, provided, however,
that Assignor, at its expense, shall have the right, but not the obligation, to
remove art work, personal property not affixed to the Leased Premises and IT
equipment (other than cabling). By way of clarification, Assignor shall not be
required to remove any fixtures, built-ins, filing cabinets, carpeting, wall
treatments, cabling, raised floors, or any other personal property. Assignor
shall not have the right to remove any other fixtures or equipment from the
Leased Premises. Assignor shall repair any damage to the Building and/or to the
portion of the Leased Premises which is caused by of arising from the removal
Assignor's personal property and Assignor shall be obligated to deliver the
Leased Premises in substantially the same condition as it exists on the dare
hereof, reasonable wear and tear excepted, without limiting the generality of
the foregoing, all systems shall be terminated in good and workmanlike manner,
in compliance with the Lease and applicable laws. An affiliate of Assignor and
Assignee are simultaneously herewith entering into a Bill of Sale (the "Bill of
Sale") with respect to the personal property which Assignor elects to leave in
the Leased Premises upon vacating the same. Nothing contained in the Bill of
Sale shall require, or be deemed to imply, that Assignor or DLJ Leasing
Corporation, the seller thereunder, has any obligation to leave certain personal
property items within the Leased Premises. Such Bill of Sale shall nor apply to
any personal property items that Assignor removes from the Leased Premises as
permitted hereunder.

       (b) Assignor is not liable or bound in any manner by expressed or implied
           warranties, guaranties, promises, statements, representations or
           information pertaining to the Leased Premises made or furnished by
           any real estate broker, agent, employee, servant or other person
           representing or purporting to represent Assignor unless the same are
           specifically set forth herein. All understandings and agreements that
           existed heretofore between the parties hereto are merged in this
           Assignment, which alone fully and completely expresses their
           agreement, and the same has been entered into after full
           investigation, neither parry relying upon any statement or
           representation not embodied in this Assignment made by or on behalf
           of the other. No warranty or representation contained in this
           Assignment shall survive the Effective Date unless specifically
           stated herein so as to survive.

    11.  NOTICES

    (a) All notices, demands or requests made pursuant to, under or by virtue of
       this Assignment must be in writing and sent to the party to which the
       notice, demand or request is being made by personal delivery, nationally
       recognized over night courier service, or postage prepaid, certified or
       registered mail, return receipt requested, as follows:

    To Assignor:

    Credit Suisse First Boston (USA), Inc. 277 Park Avenue New York, New York
10172 Attention: Raj f. Vakharia

    With a,copy to:

    Skadden, Arps, Slate, Meagher & Flom LLP 4 Times Square New York, New York
10036 Attention; Wallace L. Schwartz, Esq.

    TO ASSIGNEE:

    The Chase Manhattan Bank
270 Park Avenue
New York, New York 10017
Attention: William C. Viets, Esq.

    WITH A COPY TO:

    The Chase Manhattan Bank
2 Chase Manhattan Plaza
<PAGE>
New York, New York 10081
Attention: Ms. Leslie Whatley

    WITH AN ADDITIONAL COPY TO:

    The Chase Manhattan Bank
2 Chase Manhattan Plaza
New York, New York 10081
Attention: Peter I. Reiter, Esq.

    WITH A COPY TO:

    Jones, Day, Reavis & Pogue
599 Lexington Avenue
New York, New York 10022
Attention: Andrew J. Green, Esq.

    (i) Any such notice, demand or request shall be deemed to have been rendered
        or given on the date received, in the case of personal delivery or
        delivery by national recognized courier service, or on the date which is
        three (3) business days after mailing.

    (ii) The persons designated for receipt of such notices, demands or requests
         and the addresses to which they shall be given.or made may be changed
         or supplemented by notice given to each of the other parties listed in
         paragraph (a) of this Section and such changes shall take effect three
         (3) business days after such notice is given.

    12.  ADDITIONAL COVENANTS.

    (a) Assignee shall provide the financial information specifically set forth
       in Section 20.9 of the Lease and shall cooperate with Assignor in
       commercially reasonable respects, at no cost or liability to Assignee, in
       connection with the release of Assignor from liability under the Lease
       pursuant to said Section 20.9.

    (b) For a period of ninety (90) days after the last Remainder Space is
       delivered to Assignee, Assignor shall provide Assignee with access to a
       knowledgeable team of individuals familiar with the Dedicated Systems,
       technology systems, data centers and other Building Systems serving the
       Leased Premises in order to ensure that Assignee's employees are trained
       and familiar with all such Dedicated Systems and Building Systems.

    (c) Assignee hereby further covenants that until November 16, 2001, Assignee
       shall (i) upon request by Assignor, from time to time, deliver to
       Assignor information pertaining to Assignee's net worth and annual
       income, (ii) on or before May 1, 2001, deliver to Assignor Assignee's
       annual report, (iii) notify Assignor promptly in the event of any change
       in Assignee's credit rating, and (iv) upon request by Assignor, deliver
       to Assignor certificates of insurance indicating Assignee's compliance
       with the Lease requirements with respect to insurance, and providing for
       Assignor as an additional insured.

    (d) Assignor shall provide to Assignee copies of all service and maintenance
       logs, agreements and warranties applicable to Dedicated Systems, other
       building systems and equipment, to the extent the same are in Assignor's,
       or Assignor's agents, possession.

    (e) Assignor shall comply with the requirements of Sections 20.4 and 20.7 of
       the Lease in connection with execution and delivery of the Assignment.
       Assignee shall comply with Sections 20.4 and 20.6 of the Lease in
       connection with the execution and delivery of the Sublease.

    (f) On or prior to the last Delivery Date, Assignor shall cause the IDA
       Documents and PILOT Agreement to be terminated and shall deliver evidence
       of such termination to Assignor.

    (g) In the event that Assignor receives the consent of Landlord to assign to
       Assignee the 37th, 38th and/or 48th floors at 277 Park Avenue (space (the
       "CONTIGROUP SPACE") which is currently being
<PAGE>
       subleased (the "CONDITION SUBLEASES") by Assignor from The Contigroup
       Companies, Inc.; "CONTIGROUP"), and Contigroup shall not have exercised
       its right of recapture under the Contigroup Sublease, then Assignor
       hereby covenants that it shall assign the Contigroup Subleases to
       Assignee on the same terms and conditions as set forth herein and
       Assignee hereby covenants that it shall accept and assume the Cintigroup
       Subleases from and after the effective date of such assignment.

    13.  PARKLING ARRANGEMENT.  Assignee, in addition to this Assignment, hereby
agrees to accept and assume the lease with Manhattan Parking attached hereto as
EXHIBIT F (the "PARKING AGREEMENT"), upon the same terms and conditions as set
forth therein.

    14.  FURTHER ASSURANCES.  Each of Assignor and Assignee, at its own expense,
will execute, acknowledge and deliver all such reasonable further acts,
documents or instruments, in form reasonably satisfactory to it, and take all
such actions as may be reasonably necessary to effect this Assignment.

    15.  DISPUTE RESOLUTION.

    (a) Any and all disputes, controversies and claims (including, without
       limitation, the adjustments calculated pursuant to SECTION 4 hereof)
       arising out of or relating to this Assignment shall be settled and
       determined by arbitration in New York City pursuant to the terms and
       provisions of this SECTION 15.

    (b) If a party hereto elects to submit a dispute, controversy or claim to
       arbitration, then such patty (the "Initiating Party") must timely and
       properly elect to do so by notice (each, an "ARBITRATION NOTICE") of such
       election to the other party (the "RESPONDING-PARTY"). The Arbitration
       Notice shall set forth:

       (x) with reasonable specificity the dispute(s), controversy(ies) or
           claim(s) to be submitted to arbitration; and

       (y) appoint, and set forth the name and address of, the person who will
           act as arbitrator on behalf of the Initiating Party in connection
           with such arbitration.

    (c) (i) The Responding Party, Within five (5) business days after its
       receipt of the Arbitration Notice, shall give notice to the Initiating
       Party, which notice shall appoint, and set forth the name and address of
       a second arbitrator with respect to the dispute in question (it, being
       agreed that if (x) the Responding Party shall fail to appoint a second
       arbitrator within such five (5) business day period, and (y) such failure
       shall continue for two (2) business days after the Responding Party
       receives a notice of such failure from the Initiating Party, then the
       first arbitrator may appoint such second arbitrator), and, thereafter the
       two (2) appointed arbitrators shall promptly proceed to decide the issue
       to be determined.

        (ii) If, within five (5) business days following the appointment of the
             second arbitrator, the two (2) appointed arbitrators shall be
             unable to agree with respect to the issue to be determined, then
             the two (2) arbitrators shall appoint, by written instrument
             delivered to both the Initiating Party and the Responding Party, a
             third arbitrator with respect to the dispute in question (it being
             agreed that if the two (2) arbitrators shall fail to appoint a
             third arbitrator within the aforesaid five (5) business day period,
             then either the Initiating Party or the Responding Party may apply
             to the American Arbitration Association ("AAA") or if the AAA shall
             refuse or fail to act, to a court of competent jurisdiction in the
             State of New York, for the appointment of such third arbitrator).

       (iii) The three (3) arbitrators so appointed shall promptly proceed to
             decide the issue to be determined. The arbitrators shall be
             instructed to render a decision within eight (8) business days of
             the appointment of the third arbitrator. The written decision of
             any two (2) of the arbitrators shall be binding and conclusive upon
             both the Initiating party and the Responding Party.
<PAGE>
    (d) All the reasonable fees of the arbitrators appointed hereunder (whether
       by Assignor, Assignee, the AAA or a court) shall be paid by the
       non-prevailing party in the arbitration. In addition, the non-prevailing
       party shall reimburse the prevailing party for the reasonable
       out-of-pocket costs (including, without limitation, reasonable attorney's
       fees and the costs of witnesses and experts) incurred by the prevailing
       party in connection with the arbitration.

    (e) With respect to any conclusive and binding decision of the arbitrators
       rendered pursuant to this SECTION 15, judgment may be entered thereupon
       in any court of competent jurisdiction. In rendering their decision, the
       arbitrators shall have no power to modify any of the provisions of this
       Assignment, and the jurisdiction of the arbitrators is limited
       accordingly, it being understood that the arbitrators shall only have
       authority to decide the issue to be determined and in no event shall the
       arbitrators have the authority to award damages.

    16.  GENERAL.  (a) This Assignment contains all of the terms agreed upon
between the parties with respect to the subject matter hereof and supersedes any
and all prior written or oral understandings.

    (b) This Assignment may not be changed, modified or terminated except by an
       instrument executed by the parties hereto.

    (c) Neither this Assignment nor any interest herein or in the Lease may be
       assigned (voluntarily, by operation of law or otherwise) by Assignee
       until November 21, 2001. Any such assignment in violation of this
       SECTION 16(C) shall be null and void. Assignor shall have the right to
       cure any defaults on the part of Assignee which are outstanding as of
       November 16, 2001 upon three (3) business days notice to Assignee.

    (d) The parties do not intend to confer any rights or benefits hereunder on
       any parties other than the Landlord, the parties hereto, their successors
       and permitted assigns.

    (e) No waiver of any breach of any agreement or provision herein contained
       shall be deemed a waiver of any preceding or succeeding breach thereof or
       of any other agreement or provision herein contained. No extension of
       time for performance of any obligations or acts shall be deemed an
       extension of the time for performance of any other obligations or acts.

    (f) This Assignment shall be binding upon and inure to the benefit of
       Landlord, Assignor, Assignee and their respective successors and
       permitted assigns.

    (g) Whenever the context shall require, the singular shall include she
       plural, the plural shall include the singular and words of any gender
       shall be deemed to include words of any other gender.

    (h) This Assignment shall be governed by and in accordance with the laws of
       the State of New York applicable to contracts made and to be performed
       wholly within that State, without giving effect to the conflict-of-laws
       principles thereof.

    (i) This Assignment shall be interpreted and its terms construed without
       giving affect to any presumption against the party drafting or causing
       the drafting of the provision in question.

    (j) Assignor, in accordance with the provisions of Section 15.4 of the
       Lease, shall request an estoppel certificate from Landlord in the form of
       Exhibit G it attached hereto and made a putt hereof (the "LANDLORD
       ESTOPPEL CERTIFICATE"). In the event that Assignor shall, after making
       good faith efforts to obtain the Landlord Estoppel Certificate from
       Landlord, be unable to obtain the same, then provided that Assignor
       certifies to Assignee that the statements in the Landlord Estoppel
       Certificate are true and correct, the condition set forth in this
       subparagraph shall be deemed satisfied. Notwithstanding the foregoing,
       upon Assignee's receipt of an estoppel certificate from Landlord, then
       Assignor's certifications, to the extent covered in such estoppel
       certificate shall be deemed null and void, and to the extent not so
       covered, Assignor's certifications shall remain in effect, pursuant to
       the provisions contained in Section 6 hereof.

    (k) Assignor shall not amend, modify, waive any rights or settle any claims
       in any manner whatsoever which affects the rights and obligations of
       Tenant under the Lease in any manner whatsoever or terminate the Lease
       without Assignee's prior written consent.
<PAGE>
    IN WITNESS WHEREOF, the parties hereto have executed and caused this
Assignment to be executed on the day and year first above written.

<TABLE>
<S>                                                    <C>  <C>
                                                       CREDIT SUISSE FIRST BOSTON (USA), INC.

                                                       By:             /s/ GEORGE P. TWILL
                                                            -----------------------------------------
                                                                      Name: George P. Twill
                                                                     TITLE: MANAGING DIRECTOR

                                                       THE CHASE MANHATTAN BANK, a New York banking
                                                       corporation

                                                       By:
                                                            -----------------------------------------
                                                            Name:
                                                            TITLE:
</TABLE>

<PAGE>
STATE OF NEW YORK.  )                         ) COUNTY OF NEW YORK)

    On the 28th day of December, in the year 2000, before me the undersigned, a
Notary Public in and for said State, personally appeared George P. Twill known
to me or proved to me on the basis of satisfactory evidence to be the individual
whose name is subscribed to the within instrument as the authorized signatory of
Credit Suisse First Boston (USA),Inc., a Delaware corporation, and who
acknowledged to me that he executed the same in his capacity as such authorized
signatory, and that by his signature on the instrument, the individual, or the
person upon behalf of which the individual acted, executed the instrument.

    Given under my hand and official seal, this 25th day of December, 2000.

<TABLE>
<S>                                                    <C>
                                                       ---------------------------------------------
                                                                       Notary Public
</TABLE>

My Commission Expires:
<PAGE>
    IN WITNESS WHEREOF, the parties hereto have executed and caused this
Assignment to be executed on the day and year first above written.

<TABLE>
<S>                                                    <C>  <C>
                                                       CREDIT SUISSE FIRST BOSTON (USA), INC.

                                                       By:             /s/ GEORGE P. TWILL
                                                            -----------------------------------------
                                                                      Name: George P. Twill
                                                                     TITLE: MANAGING DIRECTOR

                                                       THE CHASE MANHATTAN BANK, a New York banking
                                                       corporation

                                                       By:            /s/ CHARLES J. MAIKISH
                                                            -----------------------------------------
                                                                     Name: Charles J. Maikish
                                                                           TITLE: S.V.P
</TABLE>

<PAGE>
STATE OF NEW YORK.   )
                        )
COUNTY OF NEW YORK)

    On the 28th day of December in the year 2000 before me, the undersigned,
personally appeared Charles J. Maikish personally known to me or proved to me on
the basis of satisfactory evidence to be the individual(s) whose name(s) is
(are) subscribed to the within instrument and acknowledged to me that he/
she/they executed the same in his/her/their capacity(ies), and that by
his/her/thier signature(s) on the instrument, the individual(s), or the person
upon behalf of which the individual(s) acted, executed the instrument.

<TABLE>
<S>                                                    <C>  <C>
                                                       By:              /s/ AZEEMA RAMIAN
                                                            -----------------------------------------
                                                                          Notary Public
</TABLE>