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                                                                    EXHIBIT 10.9

                                       - 1 -                     18 January 2001

                                  OFFICE LEASE

                           PROPERTY: FRANKFURTER WELLE

                                     between

Art Technology Deutschland GmbH
Messeturm 23, Box 23
60308 Frankfurt am Main

                                     --hereinafter referred to as the "Tenant"--

                                      and

DIFA
DEUTSCHE IMMOBILIEN FONDS AKTIENGESELLSCHAFT
Valentinskamp 20, 20354 Hamburg

                                   --hereinafter referred to as the "Landlord"--

                             as at 18 January 2001/2

                                                              CONTRACT NO 0186.3
                           (PLEASE QUOTE WITH ALL WRITTEN CONTACTS AND PAYMENTS)
                                                     PROPERTY: FRANKFURTER WELLE
                                                                     OFFICE EURO

(C) GAEDERTZ Rechtsanwalte, Hamburg


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                                TABLE OF CONTENTS

                                  OFFICE LEASE

                                     between

                         Art Technology Deutschland GmbH

                                       and

                                      DIFA

                  DEUTSCHE IMMOBILIEN FONDS AKTIENGESELLSCHAFT

<TABLE>
<S>                                                                                   <C>
SECTION  1 THE LEASED PREMISES .................................................       3
SECTION  2 DELIVERY OF THE LEASED PREMISES, AGREED USE .........................       5
SECTION  3 LEASE COMMENCEMENT DATE AND TERM OF LEASE ...........................       7
SECTION  4 TERMINATION .........................................................      10
SECTION  5 RENT AND INDEXATION .................................................      11
SECTION  6 PAYMENT OF RENT -- SECURITY FOR RENT ................................      13
SECTION  7 ANCILLARY COSTS .....................................................      14
SECTION  8 HEATING COSTS .......................................................      19
SECTION  9 MAINTENANCE AND USE OF THE PROPERTY AND THE LENS PREMISES ...........      20
SECTION  10 SUBLETTING .........................................................      23
SECTION  11 FIXTURES AND ALTERATIONS BY TENANT ADVERTISING AND SPECIAL OPERATING
              EQUIPMENT ........................................................      24
SECTION  12 IMPROVEMENTS AND STRUCTURAL ALTERATIONS BY LANDLORD ................      25
SECTION  13 LIABILITY OF LANDLORD -- NUISANCE BY THIRD PARTY ...................      26
SECTION  14 INSURANCE ..........................................................      27
SECTION  15 ACCESS TO THE LEASED PREMISES ......................................      28
SECTION  16 TERMINATION OF LEASE ...............................................      28
SECTION  17 SALE OF THE PROPERTY ...............................................      30
SECTION  18 PROPERTY DESIGNATION AND LOGO ......................................      31
SECTION  19 GENERAL PROVISIONS .................................................      31
SECTION  20 ADDITIONAL AGREEMENTS ..............................................      32
</TABLE>


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                                       -3-                       18 January 2001


                                    SECTION 1

                               THE LEASED PREMISES

(1) Landlord is the owner of the premises stretching over Bockenheimer Anlage,
Reuterweg, Gartnerweg, An der Welle, and LeerbachstraBe in Frankfurt, on which
is currently being erected the "Frankfurter Welle" Project (hereinafter also
referred to as the "Property").

(2) In the Property, Landlord will lease to Tenant the following areas ("Lease
Areas") and parking spaces (hereinafter also referred to as the "Leased
Premises"), the location of which (save for the proportional share in common
areas) can be taken from the layout plans attached hereto as

                                    EXHIBIT 1

<TABLE>
<S>                                                                     <C>
1.    Office space on 2nd floor, construction section 4,
      including proportional share in common areas                      1,273.57 m(2)

2.    Open-plan areas on 2nd floor, construction section 4,
      including proportional share in common areas                      2,300.55 m(2)

3.    Archive areas on 1st basement floor               approx.           100.00 m(2)

4.    Technical areas on 1st basement floor             approx.            10.00 m(2)

5.    Parking spaces in basement garage                                      18 units
</TABLE>

In addition, Tenant may use the public areas in the Property jointly with
others. The future address reads "An der Welle 3", 60322 Frankfurt.

(3) The size of the aforementioned Lease Areas has been determined in accordance
with the area definition (Frankfurter AufmaB) attached hereto as.


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                                    EXHIBIT 2

(4)   The exact location of the archive areas, technical areas and parking
      spaces has not yet been determined and shall be agreed on by the Parties
      within the framework of a supplement to this Lease Agreement. The
      technical area will be located right next to the telecommunication
      connection point on the Property.

      17 of the 18 parking spaces shall be available for Tenant's staff. These
      parking spaces shall lie within one coherent parking area. Landlord will
      endeavour to make available to Tenant, parking spaces near the entrance of
      the Leased Premises -- subject to the available capacities.

      One parking space shall form part of the visitors' parking area which
      shall be located in a central area of the basement garage still to be
      agreed on and which shall be available for all tenants of the Property.

(5)   To the extent that the Lease Areas set forth under SECTION (2) above
      deviate from the actual conditions of the Leased Premises by no more than
      1% in the aggregate on the basis of all of the Leased Areas set forth
      under SECTION (2) above, neither Landlord nor Tenant may claim adjustment
      of rent. If such deviation exceeds 1%, the rent will be adjusted to
      compensate such deviation in full. Upon expiry of one year after delivery
      of the Leased Premises, such adjustment of rent may no longer be claimed
      by Landlord or Tenant.

(6)   The standard fixtures and fittings of the Leased Premises are described in

            EXHIBIT 3.1 (Building Specification) and
            EXHIBIT 3.2 (Layout Plan or Basic Work)

Landlord shall fit out the Leased Premises for Tenant in accordance with the
provisions agreed on in SECTION 20 SECTION (3), ITEM 8, partly amending or
altering the aforementioned standard fixtures and fittings.


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                                    SECTION 2
                   DELIVERY OF THE LEASED PREMISES, AGREED USE

(1)   The Leased Premises will be delivered to Tenant on the Lease Commencement
      Date. On delivery, Landlord and Tenant will draw up a joint record of
      delivery recording any defects and outstanding work to be remedied or
      performed by Landlord without delay. If no defects or outstanding work are
      recorded, Tenant will have acknowledged the condition of the Leased
      Premises on signing the record of delivery as in line with the Lease,
      hidden defects excluded.

(2)   On delivery, Tenant will receive 3 sets of keys for each entrance
      including archive and technical areas and 240 code cards for access to the
      Leased Premises (however, no keys for doors inside the Leased Premises).
      Any additional keys or code cards needed by Tenant will be provided at the
      expense of Tenant.

(3)   Signboards in the central entrance area will be of uniform design and
      position. Any requests of Tenant will be taken into consideration by
      Landlord, if possible considering such uniform design. The same shall
      apply to any guiding systems. The cost of such uniform signboards and of
      any guiding system and the cost for setting up such signboards and system
      will be borne by Landlord, Any cost relating to amendments or special
      requests shall be borne by Tenant.

(4)   Tenant wishes to and will during the term of this Lease use the Leased
      Premises for the purpose of running an office, with the exception of bank
      operations and/or stock exchange operations. ("Agreed Use"). Any change in
      the type of trade / business operated in the Leased Premises will require
      the prior written consent of Landlord. Tenant shall take the sole
      responsibility that the Leased Premises are economically suitable for the
      Agreed Use. Tenant knows that the landlord of the firm of Citibank AG
      which is also leasing areas in the building section "Realteil 4" (see

                                  EXHIBIT 4.1)


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      of the Property Frankfurter Welle has bound himself by contract not to
      permit the use of any areas of "Realteil 4" by any of the companies
      listed in

                                   EXHIBIT 4.2

      and/or by any companies affiliated with said companies within the meaning
      of Section 15 AktG (German Stock Corporation Act) provided they offer
      financial services. The same shall apply to foreign companies affiliated
      with any of the companies mentioned in EXHIBIT 4.2 applying Section 15
      AktG mutatis mutandi. Said protection against competitors has to be
      observed. Tenant knows also, that Landlord has bound himself by contract
      with respect to the company Boston Consulting Group OHG not to lease to
      any of the companies listed in

                                   EXHIBIT 4.3

      any areas within "Realteil 4" accessible through the entrance marked red
      in EXHIBIT 4.1. Said protection against competitors has also to be
      observed.

(5)   Landlord has opted pursuant to Section 9 Subsection 2 of the German
      Turnover Tax Law (UStG) for value added tax in respect of the Property.
      Tenant shall use the Leased Premises solely for transactions that under
      the laws and regulations applicable on conclusion hereof are subject to
      deduction of input tax. If Tenant contrary to the foregoing stipulation
      does make transactions in the Leased Premises that exclude deduction of
      input tax pursuant to the laws and regulations applicable on conclusion
      hereof, then Tenant shall notify Landlord without delay. In that event,
      Tenant shall compensate Landlord for any disadvantage suffered by Landlord
      as a consequence of Landlord losing the right to deduct input tax.
      Further, on reasonable request of Landlord, Tenant shall provide Landlord
      with a written confirmation stating that Tenant is using the Leased
      Premises solely for transactions not excluding input tax deduction. If in
      this context Landlord has to submit further proof to the tax authorities,
      Tenant shall provide Landlord with such


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                                       -7-                       18 January 2001


      proof or directly submit such proof to the tax authorities if sufficient
      to satisfy Landlord's obligations.

(6)   Any official instructions or requirements caused exclusively by the
      general condition and/or the location of the Property shall be satisfied
      by Landlord. If an official instruction or the requirement of obtaining or
      maintaining an official permit is caused by the personal or specific
      operational conditions of Tenant or the specific conditions of Tenant's
      business, any related measures and costs shall be at the expense of
      Tenant. In that respect, Tenant shall also comply with any future official
      instructions and requirements relating to the use of the Leased Premises
      and meet the cost thereof even if directed against Landlord.

(7)   Landlord may lease areas at the Property to third parties pursuing the
      same or similar purposes as Tenant. No protection against competitors is
      granted to Tenant.

(8)   Landlord has introduced City Quartier Management for the Property. In the
      interests of the tenants of the Property, optimal marketing of the
      location by - among other things - coordinating the marketing for both the
      Property and the individual tenants or the organization of events shall be
      part of the responsibilities of the City Quartier Management. Any
      activities aiming at re-leasing the Property shall be excluded. It shall
      be at Landlord's discretion to cancel the introduction of the City
      Quartier Management at any time.

                                    SECTION 3
                    LEASE COMMENCEMENT DATE AND TERM OF LEASE

      (1)   This Lease will commence on delivery of the Leased Premises (the
            "Lease Commencement Date"). Delivery is scheduled for 1 February
            2002, provided the development plan for the premises already
            provided by Tenant,

                                   EXHIBIT 5,


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      remains unchanged and provided that neither the authority granting the
      building permit nor the responsible office for employment protection raise
      any objections as to said plan on the premises or impose any obligations.
      Otherwise the delivery date will be postponed by the necessary time.

      Provided that the Leased Premises are completed earlier, Landlord shall
      have the right to demand delivery earlier, however not prior to 1 January
      2002. If the contractors that are building the Leased Premises should have
      a claim against Landlord to postpone the agreed delivery date based on
      strike, lockout, force majeure, war, weather impacts, or based on other
      circumstances beyond their control that are not caused by fault on the
      part of Landlord, then the dates set forth in the second and the fourth
      sentence above shall be postponed by the time period by which completion
      of the Leased Premises is delayed. In that event, Landlord shall notify
      Tenant that such an impediment to construction has occurred and shall
      inform Tenant about the cause of such impediment and the time period the
      completion and thus the delivery of the Leased Premises will be delayed
      due to that impediment.

(2)   The expected week of delivery shall be notified by Landlord to Tenant in
      writing two weeks in advance, and the exact date of delivery two weeks
      prior to the date of delivery, Tenant has to take over the Leased Premises
      from said date notified to him. In the event that the scheduled dates
      mentioned in SECTION 1 are delayed by more than 3 months, Landlord shall
      have the right to rescind this Lease. Said rescission has to be declared
      in writing within one month after the ground for rescission has arisen.
      Any further claims shall be excluded unless Landlord acted wilfully or by
      gross negligence.

(3)   If the completion of the Leased Premises is delayed due to any finishing
      or installation work desired by Tenant, Tenant's duty to pay the rent
      shall be effective from the date the Leased Premises would have been
      completed without such delaying work. The same shall apply if any workmen
      or other persons commissioned by Tenant prior to the Lease Commencement
      Date should cause any damage to the Leased Premises.


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      (4)   This Lease is concluded for a fixed term of 5 years, counting from
            the first day of the month following delivery ("Fixed Term). Tenant
            shall have the right to renew the Fixed Term once by 5 years by
            unilateral declaration ("Optional Lease Term") pursuant to the
            provisions under this Lease Agreement prevailing at the time of said
            unilateral declaration ("Optional Right"). If Tenant wishes to
            exercise said Optional Right, he has to do so by notifying Landlord
            in writing at the latest 13 (thirteen) months prior the expiry of
            said Fixed Term. The provision on the aforementioned option shall
            not apply, if Tenant "sublets major parts of the Leased Premises at
            the time of exercising said option.

      (5)   If Tenant does not exercise his Optional Right, the Lease will renew
            for an indefinite period of time, unless terminated by either party
            at 12-month's notice to the end of its Fixed Term. If Tenant
            exercises said Optional Right, the Lease will renew upon expiry of
            the Optional Lease Term for an indefinite period of time unless
            terminated by either party at 12-month's notice prior to expiry of
            the Optional Lease Term.

      (6)   If Tenant continues using the Leased Premises upon expiry of the
            lease term, the Lease shall not be deemed renewed. Section 568 of
            the German Civil Code (BGB) shall be excluded.

      (7)   If the Leased Premises or a major part of the Leased Premises are
            destroyed due to an event beyond Landlord's control (e.g. fire
            etc.), it will be in the discretion of Landlord whether or not to
            reconstruct the Leased Premises. Landlord shall notify the Tenant in
            writing of his decision within 3 months following the event due to
            which the destruction / damage occurred. If Landlord decides to
            reconstruct the Leased Premises, Tenant shall remain to be bound
            under this Lease if Landlord is in a position to make the Leased
            Premises available to Tenant within 12 (twelve) months from the
            destroying or damaging event, Tenant's duty to pay the rent,
            however, shall be suspended or reduced respectively for the time
            period the Leased Premises or part of the Leased Premises cannot be
            fully used by Tenant as provided herein.


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                                    SECTION 4

                                   TERMINATION

      (1)   Any notice of termination in relation to this Lease must be given in
            writing. Notice of termination shall be deemed effected not on
            despatch but on receipt.

      (2)   On occurrence of good cause (wichtiger Grund), this Lease may be
            terminated by either party without observing any notice period.
            Moreover, Landlord may terminate this Lease without notice if:

            1.    Tenant with regard to two subsequent dates for payment is in
                  delay in paying the rent or a substantial part thereof
                  (Section 554 Subsection 1 point 1 BGB) - in spite of a
                  reminder setting a respite of two weeks sent to Tenant by
                  Landlord by registered letter with registered delivery slip or
                  another appropriate proof of delivery; or

            2.    if Tenant - in spite of a reminder setting a respite of two
                  weeks sent to Tenant by Landlord by registered letter with
                  registered delivery slip or another appropriate proof of
                  delivery- is in delay in paying the rent for a time period
                  stretching over more than two dates for payment, with regard
                  to a sum reaching the rent for two months (Section 554
                  Subsection 1 point 2 BGB); or

            3.    if Tenant is under the duty to make a statement in lieu of an
                  oath pursuant to Section 807 of the German Code on Civil
                  Procedure (ZPO), or if Tenant has initiated an out-of-court
                  procedure for the settlement of debts, or if Tenant has
                  stopped payments; or

            4.    if Tenant is in delay in furnishing the agreed securities or
                  rent and fails to provide such security within a two-weeks'
                  period of grace - set by registered letter with registered
                  delivery slip or another appropriate proof of delivery.


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                                    SECTION 5
                               RENT AND INDEXATION

(1)                     The monthly rent consists of the following:

<TABLE>
<S>                     <C>                                                  <C>   <C>
1.   3,574.12 m(2)      office space and open-plan areas on 2nd floor         =     (euro)164,481.00
                        including proportional share in common areas a
                        (euro)46.02/m(2)

2.   ca. 100.00 m(2)    Archive areas on 1st basement floor                  =     (euro)  1,026.00
                        a(euro)10.26/M(2)

3.   ca. 1O.0Om(2)      Technical areas on 1st basement floor                =     (euro)    102.60
                        a(euro)10.26/M(2)

4.   18                 Parking spaces in the basement garage                =     (euro)  4,601.70
                        a(euro)255.65/parking space

5.                      Subtotal I                                           =     (euro)170,211.30

6.                      Prepayment on ancillary costs (Section 7)            =     (euro) 20,268.19

7.                      Prepayment on heating costs (Section 8)              =     (euro)  1,506.93

8.                      Lump sum                       (Section 9(3))        =     (euro)  1,842.06
                                                                                   ----------------

9.                      Subtotal II                                          =     (euro)193,828.48
                                                                                   ----------------

10.                     Plus VAT (currently 16%)                             =     (euro) 31.012.56

11.                     TOTAL OF MONTHLY RENT                                =     (euro)224.841.04
                                                                                   ================
</TABLE>

      Also see SECTION 20 SECTION (2).

      (2)   Tenant's duty to pay the rent agreed upon in SECTION (1) above shall
            commence on the Lease Commencement Date. The same shall apply if
            Tenant despite timely notification of the delivery date by Landlord
            fails to appear on delivery of the Leased Premises or if delivery is
            not effected because no security for rent has been furnished.

      (3)   If the condition for Landlord's opting for turnover tax pursuant to
            Section 9 Subsection 2 of the German Turnover Tax Law (UStG) fails
            because of a failure of Tenant to use the Leased Premises, wholly or
            in part, in accordance with what is


                       Non-binding translation (C)GAEDERTZ




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                               WORKING TRANSLATION

                                      -12-                       18 January 2001


      agreed under SECTION 2 SECTION (5) hereof, then Landlord will no longer be
      obliged to present VAT separately. Instead, Tenant will be owing the
      previous gross rent (monthly rent without ancillary costs and heating
      costs but plus VAT) as (new) monthly rent without presentation of VAT. If
      such lack of option condition becomes known at a later stage only,
      Landlord may amend any invoice issued so far in such a way that the
      contractual gross rent paid till then corresponds with retroactive effect
      with the monthly Base Rent (without showing VAT). Any further claims of
      Landlord under SECTION 2 SECTION (5) hereof shall remain unaffected.

(4)   Both the rent (without ancillary costs and heating costs) and the lump sum
      agreed upon in SECTION 9 SECTION (3) hereof shall be subject to indexation
      as follows:

            1.    With effect as of commencement of the thirteenth month
                  following the Lease Commencement Date (beginning of second
                  lease year), the rent (without ancillary costs and heating
                  costs) and the lump sum shall be adjusted to the change in the
                  cost-of-living index for all private German households (1995 =
                  100 all-German index) occurred by then (i.e., up until and
                  including the last month of the first lease year) as compared
                  to its level in the month of the Lease Commencement Date
                  ("First Base Month").

            2.    Thereafter, the amounts set forth under point 1 above shall be
                  adjusted for every subsequent lease year in accordance with
                  the index change occurred between the index level based on
                  which the latest adjustment was made and the index level of
                  the last month of the past lease year, namely with effect as
                  of commencement of the first month of the new lease year.

            3.    The foregoing adjustments will be made automatically so that
                  the amount adjusted to the index change will be owed without
                  special request from commencement of a new lease year. As long
                  as Tenant has received from Landlord no written recalculation,
                  however, the effects of delay in payment cannot arise.


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                                      -13-                       18 January 2001


(5)   It is the mutual understanding of the Parties that the above index clause
      is deemed approved pursuant to Section 4 Subsection 1 of the German Price
      Clause Regulation (Preisklauselverordnung) of 23 September 1998 and that
      it does not unfairly prejudice any of the Parties in terms of Section 2 of
      the German Price Clause Regulation. In the event that Section 4 Subsection
      1 of the German Price Clause Regulation should be inapplicable and/or any
      required permit not be granted, the Parties agree to find an approvable
      arrangement the economic content of which comes as closely as possible to
      the index clause agreed herein.

(6)   If the index in (4) above should no longer be maintained or if it should
      be replaced with another index or switched to another base figure, then
      the changed index shall supersede the index in (4) above. Apart from that,
      the Parties are under the mutual obligation to agree also in this respect
      on a corresponding arrangement the economic content of which comes as
      closely as possible to what has been agreed upon herein.

                                    SECTION 6
                      PAYMENT OF RENT -- SECURITY FOR RENT

(1)   Each month, the rent shall be paid to Landlord in advance no later than on
      the 3rd working day of a month, at no expense to Landlord, to Landlord's
      bank account no. 00 1009 5960 with DG Bank Deutsche Genossenschaftsbank,
      Hamburg (bank code: 200 600 00) along with Tenant's identification number.
      Payments shall be deemed effected not on despatch but on being credited.

(2)   In case of delay in payment, the Parties shall be entitled to claim
      default interest in accordance with Section 288 Subsection 1 BGB.
      Landlord's right of termination as per SECTION 4 hereof shall remain
      unaffected.

(3)   By 1 March 2001 Tenant will furnish security for rent by way of a bank
      guarantee issued by a major German or European bank for the amount of 3
      times the monthly rent pursuant to Section 5, sub-section (2), item 12,
      i.e. including ancillary costs, heating costs and flat maintenance charge
      and VAT, hence for


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                                      -14-                       18 January 2001


                                (euro)674,523.12

                               (= DM 1,319,252.55)

(Euro: six hundred and seventy-four thousand five hundred and twenty-three
12/100)

(Deutsch Marks: one million three-hundred and nineteen thousand two hundred and
fifty-two 55/100)

      as specified in

                                   EXHIBIT 6.

      In addition, Tenant shall also furnish by 1 March 2001 security for rent
      in the form of a letter of support as specified by means of the example
      appended in

                                   EXHIBIT 7.

      If the securities for rent are not furnished in good time, Tenant shall
      not be allowed access to the Leased Premises prior to delivery of such
      security. Any delay caused thereby shall be imputable to Tenant; Tenant
      will not be released from any of its duties hereunder including Tenant's
      duty to pay the rent. SECTION 4 SECTION (2) SUBSECTION 4 shall remain
      unaffected.

(4)   In case of the sale of the Property, Landlord will be entitled and obliged
      to transfer the security for rent to the acquiring party.

(5)   With regard to Landlord's lien, the statutory provisions apply.

                                    SECTION 7
                                 ANCILLARY COSTS

(1)   The prepayment on ancillary costs agreed upon in SECTION 5 hereof will be
      effected with regard to the ancillary costs of the Property as set forth
      below. By way of prepay-


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                                      -15-                       18 January 2001


      ment on such ancillary costs, Tenant will each month make the following
      advance payment:

                                 (euro)20,268.19
                                 (=DM 39,641.13)

           (Euro twenty thousand two hundred and sixty-eight 19/100)

      (Deutsche Marks thirty-nine thousand six hundred and forty-one 13/00)

      plus VAT.

(2)   For purposes of this Lease, ancillary costs shall mean charges,
      contributions, fees and expenses to the extent incurring by or newly
      arising to Landlord because of the ownership or hereditary building right
      to the Property and/or the agreed use of the land, buildings or economic
      unit (an economic unit including ancillary buildings, multi-storey car
      parks and basement garages, equipment and facilities), especially the
      following costs:

      1.    all regular public charges, land tax, ground rent, domestic refuse
            disposal, collection of valuable waste materials for recycling,
            cleaning of chimneys, sewerage, water supply and drainage (including
            rainwater and surface water) as well as the corresponding counters
            plus the costs for hiring and calibration of such counters;

      2.    costs of street cleaning, clearing from snow and ice, gritting,
            cleaning and maintenance of pavements, roads, including the
            maintenance of the relevant equipment, and the costs of cleaning and
            maintenance of all outdoor facilities and playgrounds, gardening,
            including replacement or addition of plants, shrubs, and bushes;

      3.    the costs of cleaning of the building including common areas, rooms
            and facilities, entrance halls, lifts, staircases as well as all
            other parts of the building for common use, cleaning and maintenance
            of exterior glass and facade areas, as well as for pest control;


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                                      -16-                       18 January 2001


      4.    the costs of the operation and lighting of public areas and rooms as
            well as of common and exterior facilities, entrance halls, lifts,
            staircases and other parts of the building that are of common use,
            including the replacement of missing lighting, as well as regular
            safety inspections;

      5.    the costs of the operation and maintenance of the external sun
            shield installations and common technical installations and
            facilities (in particular building control systems, lifts and
            freight lifts including emergency-call systems and the costs for
            hiring such systems, escalators, fire alarm systems, CO2 alarm
            systems, fire sprinklers, butterfly dampers and smoke funnels,
            air-conditioning systems, aeration systems, cradle systems, gasoline
            separators, pumps and facilities for increasing water pressure,
            etc.), including all counting devices plus the costs for hiring and
            calibrating such equipment, and the costs of using general
            communication systems (wide-band cable, etc.);

      6.    all-risk insurance for the premises (all-risk coverage including
            insurance against loss of rent), the cost of any third-party
            liability insurance required as well as the cost of any safety
            inspections required under such insurance;

      7.    the costs of janitors or other janitorial services as well as the
            costs of monitoring services and doormen;

      8.    other costs that pursuant to Exhibit 3 to Section 27 Subsection (1)
            of the Second Calculation Ordinance (II. Berechnungsverordnung)(1)
            as amended on occurrence of costs may be allocated to tenants as
            operating costs.

(3)   For purposes of this Lease, ancillary costs shall also include the costs
      of building management. With regard to these costs, the Parties agree on a
      monthly lump sum of 4 % (four per cent) of the rent (without ancillary
      costs, advance on heating costs, lump sum as per SECTION 9 SECTION (3),
      and VAT) plus VAT in the amount prescribed by law ("Management Fee"). In
      the event that Landlord decides to with-

----------
(1)   Verordnung uber wohnungswirtschaftliche Berechnungen.


                       Non-binding translation (C)GAEDERTZ



<PAGE>

                               WORKING TRANSLATION

                                      -17-                       18 January 2001


      draw the City Quartier Mangement, said Management Fee shall be reduced to
      3.5 % (three point five of hundred) of the lease due (without ancillary
      costs and advance on heating costs, lump sum as per Section 9 Section (3)
      and VAT). Requiring no further proof, the Management Fee will be owed even
      if the Property is under the management of Landlord itself.

(4)   To the extent that ancillary costs arise anew or increase in terms of
      SECTION (2) above subject to proper management, such costs may be
      apportioned to the tenants of the Property from the date of their arising
      anew or from the date of their being increased, and Landlord may fix
      reasonable prepayments with regard to such costs. If no up-to-date
      land-tax assessment notices are available to Landlord, calculations of the
      expected land-tax burden shall apply instead.

(5)   If the aforementioned ancillary costs are apportioned among the tenants of
      the Property, then both the scale for apportionment and the accounting
      period will be determined by Landlord in Landlord's sole discretion under
      due observance of the principle of treating all tenants equally and in
      compliance with all mandatory legal rules and regulations. In case of
      doubt, these ancillary costs shall be accounted for in accordance with the
      portion of Leased Areas of the Leased Premises as compared to the leased
      areas of the entire Property. The ancillary costs to be allocated to the
      public areas within the "Frankfurter Welle" complex shall be apportioned
      on a pro-rata basis to all "Frankfurter Welle" tenants. The "Frankfurter
      Welle" complex is identified in the layout plan hereto appended as

                                   EXHIBIT 8.

      Underground parking space shall not be taken into account when calculating
      ancillary costs. Any relating ancillary costs shall be covered by the rent
      payable for such parking space.

(6)   Notwithstanding the foregoing provision, Landlord may request Tenant -- in
      as far as technically possible - to settle individual items of ancillary
      costs (such as water consumption) directly with the respective utility
      provider or to distribute costs in


                       Non-binding translation (C)GAEDERTZ
<PAGE>

                               WORKING TRANSLATION

                                      -18-                       18 January 2001


      accordance with Individual consumption of the tenants of the Property.
      Tenant agrees to keep counters and other facilities to measure consumption
      at all times accessible to Landlord.

(7)   Tenant will be responsible for proper disposal of any waste that may not
      be disposed of with domestic refuse (especially hazardous waste and
      dangerous materials as well as bulky waste such as packaging, etc.).
      Likewise, Tenant will be responsible for proper storage of such waste on a
      temporary basis until disposal thereof. Landlord, however, shall use its
      best efforts to assist Tenant to the extent local possibilities so allow.
      No refuse containers may be set up or waste or reusable material stored
      outside the areas designated by Landlord.

(8)   Once a year, Landlord will render account for Tenant's prepayments. The
      Tenant shall have the right to inspect all accounting documents at the
      Landlord's within eight weeks of receipt of the statement of account.
      Tenant shall have the right to take copies of all accounting documents
      against reimbursement of costs. Any balance between prepayments and
      accounts in favour of Landlord or Tenant will have to be settled by Tenant
      / Landlord within one month following receipt of a statement of account or
      by Tenant within one month following the expiry of the period of time
      during which inspection of the accounting documents can take place. If
      Tenant removes from the Leased Premises during a running accounting
      period, apportionment will in case of doubt be effected along with the
      next settlement of accounts in accordance with the ratio between the Lease
      Term and the Accounting Period. The right to protect the accurateness of a
      statement of account shall be excluded after expiry of one year after
      receipt of a statement of account.

(9)   If it follows from a statement of account prepared by Landlord that the
      ancillary costs have increased or decreased, the prepayments to be
      effected by Tenant for the next accounting period shall be reasonably
      increased or decreased.


                       Non-binding translation (C)GAEDERTZ
<PAGE>

                               WORKING TRANSLATION

                                      -19-                       18 January 2001


                                    SECTION 8

                                  HEATING COSTS

(1)   The prepayment on heating costs agreed upon in Section 5 hereof will be
      payable for the heating costs set forth below. By way of prepayment for
      the heating costs set forth below, Tenant will each month pay in advance

                                 (euro) 1,506.93

                                 (= DM 2,947.30)

                (Euro: one thousand five hundred and six 93/100)
        (Deutsche Marts two thousand nine hundred and forty-seven.30/100)

      plus VAT in the amount prescribed by law.

(2)   For purposes of this Lease, heating costs in particular include the costs
      of fuel and fuel supply, operating current, servicing, maintenance,
      monitoring, control of heating, fuel, and exhaust-air systems, regular
      inspection of their operational readiness and operational safety including
      expert setting, cleaning of installations and the respective rooms,
      measurements according to the German Law Concerning the Protection against
      Harmful Effects on the Environment through Air Pollution, Noise,
      Vibrations, and Similar Factors (Bundes-Immissionsschutzgesetz), rental or
      other types of transfer permitting the use of equipment for measuring
      consumption, as well as the cost for using equipment for measuring
      consumption plus calibration of such equipment including the costs for
      calculating and apportioning such costs. In case of long-distance heating,
      the heating costs further include especially the entire costs of supply of
      heating and the costs for the operation of the relevant installations at
      the complex, as well as the costs set forth above.

(3)   If Landlord provides hot water for the Leased Premises, the costs of such
      hot-water utility system will be part of the heating costs. SECTION(2)
      SENTENCE 2 above applies analogously with regard to long-distance heating.


                       Non-binding translation (C)GAEDERTZ
<PAGE>

                               WORKING TRANSLATION

                                      -20-                       18 January 2001


(4)   Prepayments will be accounted for once a year in compliance with the
      Heating Costs Ordinance (Heizkostenverordnung). In case of long-distance
      heating, Tenant's portion of heating supplies will be determined solely by
      using counters calibrated in accordance with the law. In other respects,
      the provisions of SECTION 7 apply analogously.

                                    SECTION 9

           MAINTENANCE AND USE OF THE PROPERTY AND THE LEASED PREMISES

(1)   Landlord shall be responsible for the maintenance of the Property as to
      Dach und Fach (exterior maintenance), and Landlord shall bear the relevant
      costs. For purposes of this provision, Dach shall mean the roof
      construction including covering and the pertaining plumbing work
      (gutters), including canopies, ancillary and glass roofs as well as access
      ways to and from the roof. For purposes of this provision, Fach shall mean
      the structural parts of the building (all foundations, supporting walls,
      supports, pillars, and ceilings), including facades and casings, and the
      chimney.

(2)   Moreover, Landlord shall be responsible for

      1.    the preservation and renovation of common areas, common technical
            facilities and installations outside the Leased Premises, and for
            the replacement of broken windows to the outside;

      2.    the removal of damage to the building and/or the premises caused by
            third parties such as guests or customers of Landlord;

      3.    for the procurement (including depreciation for wear and tear) of
            equipment for cleaning, removing snow and ice and for preserving the
            premises and the building including the multi-storey car
            park/basement garage, as well as for the preservation and cleaning
            of all exterior areas such as landscaped areas; and


                       Non-binding translation (C)GAEDERTZ
<PAGE>

                               WORKING TRANSLATION

                                      -21-                       18 January 2001


      4.    for the preservation and renovation of common bell, intercom and
            door-opening systems.

(3)   By way of lump-sum remuneration for the costs incurred by Landlord in
      connection with the measures set forth in SECTION (2) above, Tenant,
      irrespective of the sums actually paid, shall each month pay a sum of Euro
      0.50 per square metre, subject to adjustment pursuant to SECTION 5 SECTION
      (4) and plus VAT. Any indemnity claims of Landlord against Tenant on the
      basis of statutory or contractual provisions regarding liability shall
      remain unaffected.

(4)   Any measures for maintaining, preserving or renovating the Leased Premises
      in the interior shall rest on Tenant at Tenant's expense. This includes in
      particular the maintenance, preservation, and renovation or electric power
      and lighting systems, sanitary facilities, gas heaters etc., kitchen
      equipment, mountings, door locks, windows (inside), sun-protecting
      facilities (inside and outside), internal partitions, air-conditioning
      facilities, and room-air equipment (to the extent available in the Leased
      Premises). Lighting gear and lighting inside the Leased Premises shall be
      replaced by Tenant at Tenant's expense. Tenant shall be responsible for
      the regular inspection, maintenance and replacement of any
      fire-extinguishing gear inside the Leased Premises, even if provided by
      Landlord.

(5)   Tenant will have to carry out in regular intervals minor decorative
      repairs inside the Leased Premises.

(6)   Prior to setting up or altering technical installations which due to their
      emanations (e.g., shocks, noise, olfactory effects, vibration, hazardous
      materials, radiation, dust, gas, parasitic current) may cause nuisance to
      third parties or may endanger the premises or the building, Tenant will
      have to obtain information on the relevant rules (including rules of
      employers' liability insurance associations) and standards and obtain
      Landlord's written consent by submitting such information. Tenant may
      claim the grant of Landlord's consent if adverse effects on third parties,
      the premises, or the building can be ruled out. If such technical
      installations, however, do


                       Non-binding translation (C)GAEDERTZ
<PAGE>

                               WORKING TRANSLATION

                                      -22-                       18 January 2001


      cause nuisance to third parties or adverse effects for the premises or the
      building, then Landlord may revoke any grant effected and claim that such
      installations should be removed. If such an object causes damage to the
      premises and/or the building, Tenant will have to make good such damage.
      This shall apply analogously in case of Tenant setting up heavy apparatus,
      machinery, safes, etc. in the Leased Premises with regard to risks
      emanating from such equipment.

(7)   To the extent that Tenant handles hazardous substances or hazardous
      mixtures in the meaning of Section 3 a of the German Act on Toxic
      Substances Control (Chemikaliengesetz) or Section 4 of the Dangerous
      Substances Ordinance (Gefahrstoffverordnung), Tenant shall be obliged to
      observe all relevant rules concerning the handling of such dangerous
      substances and mixtures and indemnify Landlord against all risks and
      official requests related therewith. Landlord may claim that Tenant should
      effect and carry appropriate liability insurance to cover the handling of
      such substances and mixtures. On demand of Landlord, Tenant shall at any
      time render proof as to the conclusion as well as the scope and continued
      existence of insurance cover. Tenant has to make good any damage caused by
      any use of hazardous substances and mixtures (including the storage
      thereof).

(8)   Any damage to the premises or the building shall be notified to Landlord
      or Landlord's agent as soon as Tenant becomes aware of such damage. In
      case of imminent danger, Tenant itself shall take any measures required,
      if possible.

(9)   Tenant shall indemnify Landlord against any damage caused by Tenant
      violating its duty to take due care, especially if caused by improper
      handling of the installations, materials, or substances specified in
      SECTIONS (6) and (7) above.

(10)  Any damage covered by Tenant's scope of responsibility shall be remedied
      by Tenant without delay in coordination with Landlord. If Tenant fails to
      comply with that duty within a reasonable delay following a written
      warning, then Landlord may have the necessary work carried out at the
      expense of Tenant. The requirements


                       Non-binding translation (C)GAEDERTZ
<PAGE>

                               WORKING TRANSLATION

                                      -23-                       18 January 2001


      of written warning and setting of delay for remedying a case of damage
      shall not apply in case of imminent danger.

                                   SECTION 10
                                   SUBLETTING

(1)   Landlord hereby gives his consent to the subletting of the Leased
      Premises, wholly or in part, to a third party subject to the use agreed
      under SECTION 2 hereof, provided that the sub-letting does not infringe
      Landlord's contractual obligations as detailed in Section 2 Section (4)
      with respect to Citibank AG and Boston Consulting Group OHG.

      Tenant will have to submit to the Landlord the sublease in advance.
      Landlord may revoke his general consent pursuant to the first sentence for
      good cause only. Inter alia, it shall be considered a good cause in the
      event that the sub-tenant is a company with respect to which Landlord has
      granted another tenant of the Property protection against competitors
      prior to gaining knowledge of said sub-lease agreement and provided that
      he revokes his consent within a period of 4 weeks from receipt of the
      sub-lease agreement with reference to his obligation to grant protection
      against competitors. In these cases, any revoke by Landlord of his
      afore-mentioned consent shall not give Tenant the right to terminate the
      Lease.

(2)   Both in case of a sublease or other form of transfer permitting the use of
      the Leased Premises which has been approved by Landlord and in case of a
      sublease or other form of transfer permitting the use of the Leased
      Premises but which has not been approved by Landlord, Tenant, by signing
      the Lease, assigns to Landlord its claims against a sub-tenant along with
      any liens in order to secure any claims of Landlord, and Landlord accepts
      such assignment. If the rent realised by Tenant under a sublease exceeds
      the rent agreed upon in SECTION 5 hereof, then Tenant will each month
      effect a subsequent payment to Landlord in the amount of 50 % (fifty per
      cent) of such additional sum.


                       Non-binding translation (C)GAEDERTZ
<PAGE>

                               WORKING TRANSLATION

                                      -24-                       18 January 2001

(3)   In case of a sublease or other arrangement permitting the use of the
      Leased Premises, Tenant will be liable for any acts or omissions of such
      subtenant or user, irrespective of own fault, as if imputable to Tenant
      itself.



                                   SECTION 11
      FIXTURES AND ALTERATIONS BY TENANT ADVERTISING AND SPECIAL OPERATING
                                    EQUIPMENT

(1)   With regard to any fixtures and alterations in the Leased Premises
      including the affixing or alteration of fixed installations, Tenant will
      require the written consent of Landlord to whom Tenant shall submit
      adequate planning in advance. The same shall apply to the affixing or
      alteration of customary advertisements, signboards or other operating
      equipment outside the Leased Premises. Any consent to such measures may
      not be withheld or revoked by Landlord unless for good cause. Landlord may
      make the payment of a user fee a condition for his consent regarding
      facilities outside the Leased Premises. In addition to that, reference is
      made to SECTION 9 SECTIONS (6) to (10) AS WELL AS TO SECTION 16 SETION(6).

(2)   Any official permits required for the above-mentioned measures shall be
      procured and maintained by Tenant, and Tenant shall bear all costs
      relating to the implementation of such measures. Official permits shall be
      submitted to Landlord prior to commencement of such measures. If technical
      installations are subject to acceptance and/or regular inspection (e.g. by
      the TUV, the Technical Control Association of Germany), such acceptance or
      inspection will have to be caused by Tenant at Tenant's expense, and
      Tenant shall provide Landlord both with proof of implementation and with
      the respective results. When implementing such measures, the interests of
      the other tenants of the Property shall be taken into consideration to the
      greatest possible extent. Any noisy measures or other measures causing
      nuisance to the business of other tenants may be carried out solely in the
      morning until 09:00 hrs, on weekends or public holidays but the relevant
      legal rules and regulations will have to be observed by Tenant even on
      such occasions.


                       Non-binding translation (C)GAEDERTZ
<PAGE>

                               WORKING TRANSLATION

                                      -25-                       18 January 2001


                                   SECTION 12
               IMPROVEMENTS AND STRUCTURAL ALTERATIONS BY LANDLORD

(1)   Subject to timely announcement and even without the consent of Tenant,
      Landlord may carry out any improvements or structural alterations that may
      be required to preserve the premises, the building or economic unit, to
      ward off imminent danger, or to remedy damage. The same shall apply to
      work and structural measures that are not required but expedient, in
      particular for purposes of modernisation (in the sense that the Property
      is adapted to current building standards) or of better utilisation, or for
      extensions (including heightening). This includes structural alteration
      work carried out in connection with new leases for single rooms or in
      connection with a new design for the Property. Should any of the
      latter-mentioned measures require interferences with the Leased Premises,
      said measures shall be subject to Tenant's prior consent.

(2)   When implementing such work, Landlord shall duly consider the interests of
      Tenant. Landlord shall notify Tenant in good time prior to commencement of
      such work and structural measures and present its plans for improvement
      and/or alteration. Tenant agrees to allow reasonable access to the rooms
      and areas of the Leased Premises concerned by said measures. The Tenant's
      business operations must not be impaired to more than an insignificant
      extent due to works carried out pursuant to the above SECTION (1), SECOND
      SENTENCE; any works causing dust or noise pollution shall be carried out
      outside the Tenant's business hours, if anyhow possible.

(3)   If Landlord has carried out work and structural measures in terms of
      SECTION (1) above which cause lasting savings of heating energy or of
      other ancillary costs mentioned in SECTION 7 hereof, Tenant, by signing
      this Lease, basically agrees to bear a reasonable share of such
      investments taking into account and in accordance with Tenant's share in
      such savings and the remaining period of his lease. Tenant's share in such
      costs shall be stipulated by the Parties in an addendum hereto.

(4)   Tenant may reduce the rent or exercise a retention right if such work
      excludes or substantially affects the Agreed Use, wholly or in part.
      Section 541b Subsec-


                       Non-binding translation (C)GAEDERTZ
<PAGE>

                               WORKING TRANSLATION

                                      -26-                       18 January 2001


      tion (2) BGB shall be excluded. Any claims for damages that may be
      asserted by Tenant shall be limited in accordance with SECTION 13 hereof.

(5)   Subject to timely coordination, Tenant shall tolerate any measures for
      modernising or improving the Leased Premises in the interior, to the
      extent as may be reasonably expected from Tenant. SECTIONS (1) to (4)
      shall apply analogously.

(6)   In the event that it should be required because of a measure described
      under SECTION (1) above to provide Tenant with other lease areas on a
      temporary basis, the Parties shall enter into a separate agreement in
      which Landlord shall agree to bear Tenant's relocation costs.

(7)   Subject to the observance of the legitimate interests of Tenant, Landlord
      may lease to other tenants in the Property the facades and roofs of the
      Property for advertisements or something similar. The overall appearance
      of the Property must not be unreasonably impaired by any such measure.

                                   SECTION 13
                LIABILITY OF LANDLORD -- NUISANCE BY THIRD PARTY

(1)   Damage claims of Tenant including claims under pre-contractual obligations
      and tort may not be asserted unless arising from

      1.    wilful conduct or gross negligence of Landlord or Landlord's agents
            and servants; or

      2.    from the negligent violation of material contractual duties by
            Landlord or Landlord's agents and servants; or

      3.    from the lack of a guaranteed quality of the Leased Premises.

(2)   Landlord shall not be liable for any interference with the Agreed Use if
      caused by a third party (including other tenants of the Property).
      However, he shall be


                       Non-binding translation (C)GAEDERTZ
<PAGE>

                               WORKING TRANSLATION

                                      -27-                       18 January 2001


      obliged to immediately take all necessary (including legal) action against
      third parties and/or other tenants of the Property necessary to stop any
      interference with the Agreed Use and to prevent any repetition.

(3)   Any external circumstances not caused by Landlord (such as traffic
      diversions, ground work, roadblocks, demonstrations, nuisance through
      noise, odours or dust, as well as vibration) but interfering with the use
      of the Leased Premises shall not give rise to warranty claims of Tenant
      unless substantially affecting the Agreed Use of the Leased Premises with
      Landlord not being in a position to restrict such nuisance to a scope the
      toleration of which may be reasonably expected from Tenant. If a nuisance
      is upheld for a short time only, no warranty claims will arise to Tenant.

(4)   Tenant is aware that in the "Frankfurter Welle" complex currently some
      73,000 square metres of leased areas are being built successively. It is
      expected that for a time period of approximately 15 months from the Lease
      Commencement Date nuisance caused by construction work and finishing work
      at other lease areas and by other tenants moving in will have to be
      reckoned with, which nuisance will have to be tolerated by Tenant.
      Landlord agrees to have all tenants incur the duty to pay due regard to
      other tenants when performing any finishing work and moving in. Any claims
      of Tenant due to such nuisance shall be excluded. In the event of any
      interference of the Agreed Use by the Tenant, Section (2) shall apply
      mutates mutandis.

(5)   Any exclusions and restrictions on liability provided in this Lease shall
      also apply in favour of the agents and servants of Landlord.

                                   SECTION 14
                                    INSURANCE

(1)   Landlord may take out all-risk insurance for the building (all-risk
      coverage including insurance against loss of rent) and carry third-party
      liabiltiy insurance in a


                       Non-binding translation (C)GAEDERTZ
<PAGE>

                               WORKING TRANSLATION

                                      -28-                       18 January 2001


      scope reasonably according with risks, and such insurance shall be part of
      ancillary costs as provided for in SECTION 7 SECTION (2) SUBSECTION 6.

(2)   For purposes of the terms of insurance of the insurance contracts provided
      for in SECTION (1) above, any fixtures and alterations in or at the Leased
      Premises that increase the value of the Leased Premises, and in particular
      any change in risk assessment for purposes of the terms of insurance under
      the fire and third-party liability insurance contracts shall be notified
      by Tenant to Landlord in writing without delay. Any additional premiums
      that may accrue in that connection shall be at the expense of Tenant as
      well.

(3)   Any objects, technical equipment, advertisements or fixtures brought in by
      Tenant shall be insured by Tenant itself against damage of any type. In
      addition, Tenant shall take out and carry during the term of the Lease
      operation liability insurance and insurance against burglary and
      house-breaking.

                                   SECTION 15
                          ACCESS TO THE LEASED PREMISES

      Landlord and those designated by Landlord may enter the Leased Premises
      during regular business hours together with other parties involved,
      experts or witnesses in order to exercise a statutory lien, inspect the
      structural condition of the Leased Premises or the working order and
      safety of technical facilities in the Leased Premises, their repair or
      maintenance, to re-lease or sell the Leased Premises, or in similar cases.
      Save as in case of imminent danger, any access by Landlord shall be
      notified in good time.

                                   SECTION 16
                              TERMINATION OF LEASE

(1)   Until termination hereof, Tenant shall in any event remedy any damage
      occurred due to Tenant's using the Leased Premises as well as remove any
      hazardous material and mixtures taken by Tenant into the Leased Premises
      when using the Leased Premises, carry out any minor decorative repairs due
      and, if required, re-


                       Non-binding translation (C)GAEDERTZ
<PAGE>

                               WORKING TRANSLATION

                                      -29-                       18 January 2001


      store the original condition of the Leased Premises as specified in
      SECTION 11 SECTION (2) hereof. No later than one month prior to the
      termination of this Lease, the Parties shall draw up a joint protocol to
      record any damage occurred due to Tenants using the Leased Premises, any
      minor decorative repairs to be carried out by Tenant (also with regard to
      floor coverings), as well as the fixtures and alterations, advertisements
      and/or other facilities to be removed by Tenant.

(2)   As the Leased Premises are delivered to Tenant for initial occupation,
      Tenant, in addition to the provision in Section (1) above, shall fully
      renovate the leased Premises (except for its portion of public areas).
      Tenant's obligation to renovate the Leased Premises in any event includes
      the renewal of wall paper and the painting of walls and ceilings,
      carpeting and floor covering subject to similar wear and tear, in the
      quality available on delivery of the Leased Premises. Any carpeting or
      floor covering subject to similar wear and tear but no older than five
      years just require skilful cleaning. Colours and patterns of carpeting,
      wall paper and/or painting for walls and ceilings shall be coordinated
      with Landlord.

(3)   In case of the termination of the Lease, Tenant, on the date coordinated
      with Landlord, shall return the Leased Premises in accordance with this
      Lease, properly vacated and along with all keys and code cards and any
      additional keys that may have been produced by Tenant. If Tenant fails to
      return such items despite receipt of a warning with Landlord setting a
      period of grace, Landlord may replace the corresponding locks at the
      expense of Tenant and have produced new keys and code cards. On return of
      the Leased Premises, Landlord will draw up a record specifying the
      condition of the Leased Premises. Tenant will personally assist in drawing
      up such record or appoint an agent for that occasion in writing.

(4)   If the work to be carried out by Tenant in the Leased Premises is not
      completed by the end of this Lease, Tenant shall continue paying the rent
      plus ancillary costs until the end of the month in which such work is
      completed. Any further claims of Landlord shall remain unaffected.


                       Non-binding translation (C)GAEDERTZ
<PAGE>

                               WORKING TRANSLATION

                                      -30-                       18 January 2001


(5)   In case of the premature removal of Tenant, Landlord may also have other
      renovation and alteration work carried out in the Leased Premises without
      Tenant being entitled to claim any credit against the rent etc.

(6)   Moreover, on termination of this Lease, Tenant shall be obliged to restore
      the Leased Premises to the standard fit-out reflected in Exhibits 3.1 and
      3.2 by removing any fixtures or alterations deviating from said standard
      fit-out. Said obligation to restore the premises shall also include the
      removal at the computer system ca provided by Tenant. Said obligation to
      restore the premises shall not apply where a succeeding tenant accepting
      the specific fixtures/alterations by Tenant and assuming the related duty
      to restore the Leased Premises is willing to take over the premises. Both
      Landlord and, Tenant - each one for himself - shall be entitled to
      request redemption of the aforementioned obligation to restore the
      premises as well as of Tenant's obligation to renovate the premises
      pursuant to SECTION (2) by payment of an amount equivalent to the costs to
      be expected in case of restoration/renovation, provided that said claim
      for redemption is notified in writing to the other Party at the latest 6
      months prior to expiry of the Lease. If the Parties fail to agree on the
      redemption amount, such matter shall be solved by an arbitration expert to
      be appointed by the local chamber of crafts, the costs of such arbitral
      expert to be shared equally between the Parties.

                                   SECTION 17
                              SALE OF THE PROPERTY

(1)   Landlord reserves the right to sell the Property. When selling the
      Property, Landlord shall cause the relevant purchaser to assume all rights
      and duties under this Lease when taking over the Property. Subject to the
      above, Tenant on conclusion hereof waives its rights under Section 571
      Subsection (2) BGB (liability of a Landlord selling leased premises with
      regard to the continued fulfilment of a lease by the acquiring party).

(2)   In case of the sale of the Property, Landlord may request Tenant for a
      declaration of completeness by submitting a list of all lease documents.
      Tenant will then be


                       Non-binding translation (C)GAEDERTZ
<PAGE>

                               WORKING TRANSLATION

                                      -31-                       18 January 2001


      obliged to confirm to Landlord in writing within four weeks as to whether
      Landlord's list is complete and accurate.

                                   SECTION 18
                          PROPERTY DESIGNATION AND LOGO

Tenant shall be entitled to utilize in its business correspondence the logo
developed for the Property as identified in

                                    EXHIBIT 9

in order to identify the location of its business premises. The same shall apply
to the designation "Frankfurter Welle".

                                   SECTION 19
                               GENERAL PROVISIONS

(1)   Several natural or legal persons shall be liable as joint and several
      debtors for any liabilities under this Lease.

(2)   In the event that one or several provisions of this Lease should be or
      become invalid for whatsoever reason, this shall not affect the validity
      of the remainder hereof. In such a case the Parties shall agree on a valid
      provision accomplishing the economic purpose of such invalid provision to
      the best possible extent.

(3)   No oral ancillary agreements have been made between the Parties. Any
      amendments to this Lease as well as any other declarations of intent to be
      made by a party to the other must be in writing in order to become
      effective.

(4)   The Parties are under the mutual obligation to do any act or make any
      declaration required at any time to satisfy the legal requirement of
      writing, in particular in connection with the conclusion of any addenda,
      amendments or supplements hereto, and the Parties agree not to prematurely
      terminate this Lease until such require-


                       Non-binding translation (C)GAEDERTZ
<PAGE>

                               WORKING TRANSLATION

                                      -32-                       18 January 2001


      ments have been satisfied, by invoking any non-observance of the legal
      form of writing.

                                   SECTION 20
                              ADDITIONAL AGREEMENTS

(1)   For purposes of furthering a relationship based on partnership, Landlord
      will try to meet with Tenant once a year in order to be available as an
      on-site contact.

(2)   Until 31 December 2001, all sums mentioned in this Lease in Euro may as
      well be paid in their DM equivalent. In DM, the rent shown in SECTION 5
      hereof in Euro consists of the following:

<TABLE>
<S>                                                                              <C>      <C>
     3,574.12 m(2) office space and open-plan areas on 2nd floor                 =        DM 321,696.67
     including proportional share in common areas

     ca. 100.00 m(2) Archive areas on 1st basement floor                         =        DM   2,006.68

     ca. 10.00 m(2) Technical areas on 1st basement floor                        =        DM     200.67

     18 Parking spaces in the basement garage                                    =        DM   9,000.14

                    Subtotal I                                                   =        DM 332,904.36

                    Prepayment on ancillary costs (Section 7)                    =        DM  39,641.13

                    Prepayment on heating costs (Section 8)                      =        DM   2,947.30

                    Lump sum (Section 9 (3))                                     =        DM   3,602.76
                                                                                          -------------
                    Subtotal II                                                  =        DM 379,095.55

                    Plus VAT (currently 16%)                                     =        DM  60,655.29
                                                                                          -------------
                    TOTAL OF MONTHLY RENT                                        =        DM 439,750.84
                                                                                          =============
</TABLE>

(2)   in addition to the foregoing provisions, Landlord and Tenant agree on the
      following special provisions which in any event shall take precedence over
      the forego-


                       Non-binding translation (C)GAEDERTZ



<PAGE>

                               WORKING TRANSLATION

                                      -33-                       18 January 2001


ing provisions of this Lease. In case of any contradiction, gap, or uncertainty,
this Lease shall be interpreted in such a way that the purpose of the following
special provisions may be accomplished to the extent possible and, in other
respects, in such a way as the Parties in case of doubt had agreed upon had they
been aware of and considered such contradiction, gap or uncertainty when
entering into this Lease.

1.    Where Tenant's measures for the finishing or equipment of the Leased
      Premises should have any effect on other parts of the building, in
      particular, on the building engineering of the Property, Tenant agrees to
      commission primarily such companies that are still under certain warranty
      duties with regard to the structural or technical parts in question. If
      Tenants decides to commission another company, Tenant shall indemnify
      Landlord from any disadvantage possibly resulting from Landlord losing any
      warranty claim. This shall not apply if no fair-market offer was made to
      Tenant by the company that is still under said warranty duty.

2.    Tenant agrees to pay due regard to the other tenants of the Property when
      finishing and moving into the Leased Premises, i.e., Tenant shall in
      particular reduce any nuisance caused by dust and noise, quickly complete
      its removal and guarantee that all other leased premises may be freely
      entered.

3.    Tenant is aware that possibly the underground garage of the Property may
      not be used before December 2001. Therefore, Tenant's duty to pay rent for
      the 18 parking spaces in the underground garage as laid down in SECTION 5
      SECTION (1) SUBSECTION 1.5 will not commence until such parking spaces
      have been delivered to Tenant.

4.    Until the full completion of the Property, domestic waste will be disposed
      of in a provisional manner only.

5.    Landlord plans to set up an indoor telecommunications network for mobile
      telecommunication using the networks D1, D2, E-Plus, and Viag Interkom, as


                       Non-binding translation (C)GAEDERTZ
<PAGE>

                               WORKING TRANSLATION

                                      -34-                       18 January 2001


      well as UMTS-capable power supply. Tenant shall have no claim with regard
      to such facilities, but Tenant agrees that antennas with a radiation
      exposure ranging in a milliwatt area may be set up also in the Leased
      Premises.

6.    Landlord gives his consent to the assignment of all rights and obligations
      under the contractual relationship by Tenant to any affiliate company of
      Tenant pursuant to Section 15 AktG (German Stock Corporation Act) on the
      condition that said assignment of rights and obligations shall not become
      effective until the tenant taking over has delivered to Landlord a bank
      guarantee made out to the new tenant pursuant to EXHIBIT 6 and a letter of
      support pursuant to EXHIBIT 7 which was correspondingly, amended. Provided
      that said letter of support is to be issued by another patron, Landlord's
      consent is required.

7.    In principle, Landlord shall provide Tenant upon Tenant's written request
      with additional refrigeration power of 60 watt from a central
      refrigeration machine per 1 m(2) of leased area pursuant to Section 1
      Section (2) items 1 and 2. Tenant shall bear all related costs. If
      necessary, details shall be provided for in a supplement.

8.    Upon Tenant's request, Landlord shall build out the Leased Premises in
      accordance with

                                    EXHIBIT 5

      (Tenant's Build-Out Plan). However, Landlord shall not be under the
      obligation to provide the furniture marked in EXHIBIT 5 or the computer
      system cabling of the Leased Premises. Provided that and in so far as on
      the basis of Tenant's build out plan in accordance with EXHIBIT 5 any
      additional costs are incurred compared with the standard fit-out of the
      Leased Premises described in EXHIBITS 3.1 and 3.2, Tenant shall bear said
      additional costs up to the maximum amount of (euro) 511,291.88 (= DM 1
      million) plus VAT. Any costs exceeding the aforementioned maximum amount
      shall be borne by Tenant only if the authority granting the building
      permit and/or the responsible office for employment protection attach any
      burdens/charges/obligations to any neces-


                       Non-binding translation (C)GAEDERTZ
<PAGE>

                               WORKING TRANSLATION

                                      -35-                       18 January 2001


      sary permits/licenses causing said additional costs and/or Tenant requires
      any additional services not mentioned in EXHIBIT 5.

(4)   EXHIBITS 1.1 to 1. AS WELL AS EXHIBITS 2 TO 9 as appended hereto are
      incorporated herein by way of this reference.

      Hamburg, _______________                    ______________,_______________

DIFA
DEUTSCHE IMMOBILIEN FONDS
AKTIENGESELLSCHAFT

      ________________________                    ______________________________
            (Landlord)                                    (Tenant)

EXHIBIT 1   Office and Open Plan Areas
EXHIBIT 2   Definition of Areas
EXHIBIT 3.1 Building Specification
EXHIBIT 3.2 Layout Plan for Basic Work
EXHIBIT 4.1 Realteil 4 Plan
EXHIBIT 4.2 Black List Protection Against Competitors Citibank
EXHIBIT 4.3 Black List Protection Against Competitors Boston Consulting Group
EXHIBIT 5   Development Plan - Tenant's Build-Out Plan
EXHIBIT 6   Bank Guarantee
EXHIBIT 7   Letter of Support
EXHIBIT 8   Layout Plan Area Frankfurter Welle
EXHIBIT 9   Logo Frankfurter Welle