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                                                                    Exhibit 10.6

                                                                   June 15, 2000


Xpedior Incorporated
One North Franklin, Suite 1500
Chicago, Illinois  60606
     Attention: President and Chief Executive Officer


Ladies and Gentlemen:

1.   Reference is made to the 7% Convertible Subordinated Promissory Note Due
     2002 dated as of September 24, 1999 in the original principal amount of
     $405,337.05 (the "Note") of Xpedior Incorporated, a Delaware corporation
     (the "Company"), issued to Ann Armstrong (the "Holder"). Terms defined in
     the Note and not otherwise defined herein are used herein with the meanings
     so defined.

2.   Notwithstanding anything in the Note to the contrary:

     (a)  A portion of the principal amount of the Note in the amount of
          $215,234.05 shall be automatically converted by the Holder into 13,019
          fully paid and nonassessable shares of Stock (the "Shares") on the
          date hereof immediately prior to the merger (the "Merger") of PSINet
          Shelf IV Inc., a Delaware corporation, with and into Metamor
          Worldwide, Inc., a Delaware corporation ("Metamor");

     (b)  Immediately prior to the Merger, the Company shall prepay $190,103.00,
          in cash, in principal amount of the Note representing the remaining
          principal amount of the Note after conversion of a portion of the Note
          pursuant to paragraph 2(a); and

     (c)  $20,600.01 representing all interest on the Note accrued and unpaid
          through the date hereof shall be paid promptly, in cash, after
          conversion of a portion of the Note pursuant to paragraph 2(a) and
          payment of the remaining principal amount of the Note pursuant to
          paragraph 2(b) but in no event later than three business days after
          the date hereof.

3.   The Holder hereby directs the Company to pay $192,764.44 of the cash
     amounts payable to it pursuant to Sections 2(b) and 2(c) to Mark Hansen.

4.   The Holder acknowledges and agrees that effective upon conversion of the
     Note pursuant to paragraph 2(a) and the prepayment of a portion of the
     principal amount of the Note pursuant to Section 2(b) above, the Note shall
     be deemed satisfied, paid in full
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     and shall be cancelled and of no further force or effect and the
     Subordinated Guaranty entered into by Metamor and the Holder with respect
     to the Note shall automatically be terminated and of no further force or
     effect.

5.   If (a) the aggregate amount of proceeds that the Holder receives from her
     sales of Shares to a third party or third parties within the 14 month
     period following the date hereof (without reduction for brokers and
     underwriters commissions, discounts and fees and transaction and similar
     fees and expenses) is less than (b) the aggregate amount of proceeds that
     the Holder would have received from a sale of such Shares at a per share
     price equal to $16.5312, the Company shall promptly after the expiration of
     such 14 month period (or, if earlier, after the Holder has sold all of her
     Shares), pay to the Holder an amount equal to such shortfall, provided that
     the Holder shall use all reasonable efforts to sell the Shares at the best
     available price and terms at the time of sale. All payments required to be
     made by the Company pursuant to this paragraph shall be subordinated to all
     present and future amounts that may be owing to any senior lender to the
     Company on such form and terms as may reasonably be required by such senior
     lender. The Holder shall execute all documents reasonably required by any
     such senior lender to evidence such subordination.

6.   The Holder shall be entitled to the following registration rights:

     (a)  Piggy-back Registration. If at any time after the Company has become
          eligible to file a Registration Statement on Form S-3 (or any
          successor form), Mark Hansen shall cause the Company to prepare and
          file with the SEC a registration statement on Form S-3 relating to an
          offering for his account under the Securities Act of any of his Stock
          pursuant to Annex I of the Note referred to in the letter agreement
          dated June 15, 2000 between the Company and Mark Hansen, the Company
          shall send to the Holder written notice of such filing and, if within
          20 days after receipt of such notice, the Holder shall so request in
          writing, the Company shall include in such registration statement all
          or any part of the Shares the Holder requests to be registered;
          provided, however, that the Company shall not be required to register
          any Shares pursuant to this paragraph that are eligible for sale
          pursuant to Rule 144 under the Securities Act. If the total amount of
          securities, including Shares of the Holder, to be included in such
          registration statement exceeds the amount of securities that the
          managing underwriter (or, if the offering is not being underwritten,
          the Company's Board of Directors) determines, in its written opinion,
          in good faith is compatible with the success of the offering, then the
          number of shares that may be included in the registration statement
          shall be allocated as follows: (1) first, to the Company or, if the
          offering is being made for the account of persons other than the
          Company, such persons (2) second, to such other persons who are
          participating in such offering who have the right to include their
          shares in such registration statement on a priority basis to other
          persons participating in such offering
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          (other than the persons described in clause (1)), and (3) to the
          Holder and to any other persons participating in such offering on a
          pro rata basis based on the number of shares of securities that each
          Holder and such other persons have the right to request to be included
          in such registration.


     (b)  Underwriting Agreements, etc. As a condition to participation in any
          underwritten offering the Holder shall enter into such underwriting,
          lock-up and other agreements, and execute such other instruments, as
          is customary in an underwritten offering. As a condition to
          participation in any non-underwritten offering, the Holder shall
          cooperate to provide such information necessary for the preparation of
          the registration statement as is customary in a non-underwritten
          offering. The Holder may not participate in any registration hereunder
          unless the Holder executes and delivers an agreement not to divulge
          any proprietary or confidential information of the Company or any of
          its subsidiaries which becomes known to the Holder in connection with
          any such registration.

7.   The Company shall reimburse the Holder for all reasonable expenses incurred
     by the Holder in connection with a sale by the Holder of any or all of the
     Holder's Shares in a transaction effected pursuant to Rule 144 under the
     Securities Act other than brokers fees, commissions, discounts, mark-ups
     and mark-downs.

8.   The Holder hereby confirms that her representations and warranties set
     forth in Section 3(b)(v) of the Stock Purchase Agreement dated as of
     September 17, 1999 by and among the Company, Kinderhook Systems, Inc., the
     Holder and the other parties thereto are true and correct as of the date
     hereof.

9.   The Holder hereby represents that she has good and valid title to the Note
     free and clear of all liens, pledges, mortgages, security interests and
     other encumbrances.



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                                      -3-
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     If the foregoing is in accordance with your understanding of our agreement,
kindly sign this letter in the space provided below, whereupon this letter will
become a binding agreement between us.



                                    /s/ Ann Armstrong
                                    -----------------------------
                                    Ann Armstrong


                                    XPEDIOR INCORPORATED


                                    By /s/ Caesar J. Belbel
                                       --------------------------
                                     Title: Senior Vice President