Document:

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                                                                     Exhibit 4.1

                                   CERTIFICATE
                                     OF THE
                            DESIGNATIONS, PREFERENCES
                      AND RELATIVE, PARTICIPATING, OPTIONAL
                          AND OTHER SPECIAL RIGHTS AND
                  QUALIFICATIONS, LIMITATIONS AND RESTRICTIONS
                                     OF THE
             SERIES A 8-1/2% CUMULATIVE CONVERTIBLE PREFERRED STOCK
                                       OF
                              XPEDIOR INCORPORATED

                         Pursuant to Section 151 of the
                             General Corporation Law
                            of the State of Delaware

         I, David N. Campbell, President and Chief Executive Officer of Xpedior
Incorporated, a corporation organized and existing under the General Corporation
Law of the State of Delaware (the "CORPORATION"), do hereby certify that the
Board of Directors of the Corporation, at a meeting, adopted the following
resolution, which resolution remains in full force and effect on the date
hereof:

                  RESOLVED: That, pursuant to the authority conferred upon the
Board of Directors of the Corporation by its Certificate of Incorporation (the
"CERTIFICATE OF INCORPORATION"), and pursuant to the provisions of Sections 151
and 157 of the General Corporation Law of the State of Delaware, a series of
Preferred Stock of the Corporation be and hereby is created, classified and
authorized, and the issuance thereof is provided for, and that the designation
and number of shares, and the preferences and relative, participating, optional
and other special rights and qualifications, limitations and restrictions shall
be as set forth in the following Sections 1 through 9 (in addition to those set
forth in the Certificate of Incorporation which are applicable to all classes
and series of Preferred Stock) and in EXHIBIT A attached hereto and made a part
hereof:

                  Section 1. Designation, Number and Par Value. The series of
preferred stock shall be designated as the Series A 8-1/2% Cumulative
Convertible Preferred Stock (the "SERIES A PREFERRED STOCK"), and the number of
shares so designated shall be 1,000,000 (which shall not be subject to increase
without the prior approval of the holders (each holder of shares of Series A
Preferred Stock, a "HOLDER" and, together with all other Holders, the "HOLDERS")
of at least two-thirds of the shares of Series A Preferred Stock then
outstanding). Each share of Series A Preferred Stock shall have a par value of
$.01 per share and a stated value of $50 per share (the "STATED VALUE").
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                  Section 2. Dividends.

                  (a) (i) Holders shall be entitled to receive, when, as and if
declared by the Board of Directors out of funds legally available therefor, and
the Corporation shall, to the extent funds are legally available therefor, pay
on each Dividend Payment Date, in arrears, cumulative dividends on the Series A
Preferred Stock at the rate per share (as a percentage of the Stated Value per
share) equal to 8-1/2% per annum, payable in cash or shares of Common Stock, or
any combination thereof, at (subject to the terms and conditions set forth
herein) the option of the Corporation. Dividends on the Series A Preferred Stock
shall be calculated on the basis of a 360-day year, shall accrue daily
commencing on the date of the first issuance of any shares of the Series A
Preferred Stock, and shall be deemed to accrue on such date whether or not
earned or declared and whether or not there are profits, surplus or other funds
of the Corporation legally available for the payment of dividends. The party
that holds of record the Series A Preferred Stock on the record date for the
applicable Dividend Payment Date for any dividend payment shall be entitled to
receive, when, as and if declared by the Board of Directors out of funds legally
available therefor, such dividend payment and any other accrued and unpaid
dividends which accrued prior to such Dividend Payment Date, without regard to
any sale or disposition of such Series A Preferred Stock subsequent to the
applicable record date but prior to the applicable Dividend Payment Date. Except
as otherwise provided in the Certificate of Incorporation or this Certificate of
Designations, and except as otherwise required by law, if at any time the
Corporation pays a portion, but less than the total amount, of dividends then
accrued on account of the Series A Preferred Stock, such payment shall be
distributed ratably among the Holders based upon the number of shares held by
each Holder. In order for the Corporation to exercise its right to pay dividends
in shares of Common Stock on a Dividend Payment Date, the Corporation shall, no
less than 30 days prior to the Dividend Payment Date, provide each Holder notice
(the "COMMON STOCK DIVIDEND NOTICE") of its intention to pay dividends in shares
of Common Stock. If the Corporation elects to pay dividends in shares of Common
Stock, then the number of shares of Common Stock issuable with respect to each
share of Series A Preferred Stock outstanding on the record date for payment of
such dividend shall be equal to the aggregate dollar value of all dividends then
payable in respect of such share, divided by the Five Day Average Market Price
at the applicable Dividend Payment Date.

                           (ii) If, and so often as, the Corporation shall be in
default in the payment of dividends on the Series A Preferred Stock in an amount
equivalent to six quarterly dividends (whether or not consecutive, earned or
declared), the number of directors of the Corporation shall thereupon, and until
all dividends in default shall have been paid, be two more than the full number
constituting the Board of Directors immediately prior to such default. The
Holders, voting separately as a class, shall be entitled to elect two directors
(the "SERIES A PREFERRED STOCK DIRECTORS") to fill the vacancies resulting from
such increase, and the Holders may, at a meeting called and held as hereinafter
provided, elect such Series A Preferred Stock Directors to hold office until the
next annual meeting of shareholders. When the special class voting rights
provided for in this Section 2(a)(ii) shall have become vested, they shall
remain so vested at each succeeding meeting of shareholders for the election of
directors; provided, however, that such special voting rights shall become
divested, and the terms of office of the Series A Preferred Stock Directors
shall terminate, if and when all dividends then in default on the Series A
Preferred Stock shall be paid, but always subject to the same provisions for the
vesting of such special rights in case of further like defaults in the payment
of dividends. No
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Series A Preferred Stock Director shall, during his or her term of office, be
removed from office except upon the vote of the Holders, voting separately as a
class, and, regardless of any provision of the Corporation's By-laws, any
vacancy caused by the death, resignation, inability to serve or removal of any
Series A Preferred Stock Director shall be filled only by the vote of the
Holders, voting separately as a class, at a special meeting of the Holders
called for such purpose, or at the next annual meeting of shareholders. Whenever
the Holders become entitled to elect Series A Preferred Stock Directors pursuant
to this Section 2(a)(ii), a meeting of the Holders shall be held upon call by
the Secretary of the Corporation within 60 days after receipt of a request in
writing of the Holders of not less than 10% of the Series A Preferred Stock then
outstanding, addressed to the Secretary at the principal office of the
Corporation; provided, however, that the Corporation shall not be required to
call such a special meeting if the annual meeting of shareholders is to be held
within 90 days after the date of receipt of such request. The Corporation shall
pay all reasonable expenses incurred in connection with the calling and holding
of any such meeting (and the solicitation of proxies therefor), and the notice
of the meeting shall be accompanied by a proxy statement containing such
material as is then required by the applicable rules and regulations of the
Securities and Exchange Commission. At all meetings of shareholders held for the
purpose of electing Series A Preferred Stock Directors, the presence in person
or by proxy of the Holders of 40% of the outstanding Series A Preferred Stock
shall be required to constitute a quorum of such class for the election of
Series A Preferred Stock Directors; provided, however, that the absence of a
quorum of the Holders of Series A Preferred Stock shall not prevent the election
at any such meeting (or any adjournment thereof) of any other directors by the
holders of all other classes of shares having voting rights for the election of
directors if the necessary quorums are present in person or by proxy at such
meeting; provided further, however, that, in the absence of a quorum of the
Holders of Series A Preferred Stock, the Holders of a majority of the shares of
Series A Preferred Stock who are present in person or by proxy shall have the
power to adjourn the election of the Series A Preferred Stock Directors from
time to time, without notice other than an announcement at such meeting (or
adjournment thereof), until the Holders of the requisite number of shares of
Series A Preferred Stock shall be present in person or by proxy.

                           (iii) Notwithstanding anything contained in the
Certificate of Incorporation or this Certificate of Designations to the
contrary, no dividends or distributions on shares of Series A Preferred Stock
shall be declared by the Board of Directors of the Corporation or paid or set
apart for payment by the Corporation at such time as the terms and provisions of
any agreement, instrument or indenture of the Corporation relating to its
indebtedness specifically prohibits such declaration, payment or setting apart
for payment or provides that such declaration, payment or setting apart for
payment would constitute a breach thereof or a default or event of default
thereunder; provided, however, that nothing contained in the Certificate of
Incorporation or this Certificate of Designations shall be construed or deemed
to require the Board of Directors to declare, or the Corporation to pay or set
apart for payment, any dividends or distributions on shares of Series A
Preferred Stock at any time, whether permitted by any of such agreements,
instruments or indentures, or not.

                  (b) Notwithstanding anything to the contrary contained in
Section 2(a)(i), the Corporation may not pay dividends on the Series A Preferred
Stock in shares of Common Stock (and, except as otherwise provided below, must
deliver cash in respect thereof) if, at the date of declaration of such
dividend:
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                           (i) (A) the number of shares of Common Stock at the
time reserved for issuance for the payment of such dividends in shares of Common
Stock on such Dividend Payment Date, together with the number of shares of
Common Stock held as treasury stock, are insufficient to satisfy the
Corporation's then existing obligations to issue shares of Common Stock for the
payment of such dividends in shares of Common Stock on such Dividend Payment
Date, or (B) the number of shares of Common Stock equal to the sum of (I) the
number of shares of Common Stock at the time reserved for issuance in payment of
dividends upon, or upon conversion of, the Series A Preferred Stock, (II) the
number of authorized but unissued shares of Common Stock not reserved for any
purpose, (III) the number of shares of Common Stock at the time reserved for
issuance for all other purposes, and (IV) the number of shares of Common Stock
held as treasury stock, is insufficient to satisfy the Corporation's then
existing obligations to issue shares of Common Stock for all purposes (including
the conversion of shares of Series A Preferred Stock);

                           (ii) the shares of Common Stock payable as a dividend
on the Series A Preferred Stock are not designated for quotation on the Nasdaq
National Market or listed on the New York Stock Exchange or the American Stock
Exchange;

                           (iii) the Corporation has failed to timely satisfy
its obligations with respect to any Conversion Notice and such failure shall be
continuing as of such Dividend Payment Date;

                           (iv) the aggregate number of shares of Common Stock
(A) then held by the Holders (or former Holders) of Series A Preferred Stock
which were issued upon the conversion of shares of Series A Preferred Stock, (B)
then issuable upon conversion of any shares of Series A Preferred Stock held by
the Holders, and (C) then held by the Holders (or former Holders) which were
received as payment of dividends upon shares of Series A Preferred Stock,
including in payment of the current dividend, exceeds (I) prior to the Three
Year Date, ___________ shares (which amount is equivalent to 15% of the
aggregate number of outstanding shares of Common Stock as of the Commencement
Date), or (II) on or after the Three Year Date, ___________ shares (which amount
is equivalent to 17.5% of the aggregate number of outstanding shares of Common
Stock as of the Commencement Date), as such amounts may be adjusted to reflect
the occurrence of any of the events described in Sections 5(c)(ii), 5(c)(iii) or
5(c)(iv); or

                           (v) at any time prior to the Three Year Date, the
Five Day Average Market Price at the applicable Dividend Payment Date is less
than $10 per share (subject to adjustment for stock splits, reverse stock
splits, recapitalizations and similar events).

                  (c) (i) So long as any shares of Series A Preferred Stock
shall remain outstanding, neither the Corporation nor any of its subsidiaries or
affiliates shall (A) redeem, purchase or otherwise acquire, directly or
indirectly, any Junior Securities other than the repurchase of Common Stock
pursuant to employment agreements or employee or director benefit or stock
plans, (B) directly or indirectly pay or declare any dividend or make any
distribution upon, nor shall any distribution (other than a dividend or
distribution described in Sections 5(c)(ii) or 5(c)(iii)) be made in respect of,
any Junior Securities, or set aside any funds for any such payment or
distribution, or (C) set aside any funds for or apply any funds to the
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purchase, redemption or acquisition (through a sinking fund or otherwise) of any
Junior Securities.

                           (ii) So long as any shares of Series A Preferred
Stock shall remain outstanding, neither the Corporation nor any of its
subsidiaries or affiliates shall take any of the actions set forth in Section
2(c)(i) with respect to Parity Stock, if any, (A) unless and until the
Corporation shall have taken substantially similar actions with respect to the
Series A Preferred Stock, or (B) in a manner or on terms more favorable to the
holders of such Parity Stock, if any, than to the Holders of the Series A
Preferred Stock.

                  Section 3. Voting Rights.

         Except as otherwise provided in the Certificate of Incorporation or
this Certificate of Designations, and except as otherwise required by law, the
Series A Preferred Stock shall have no voting rights; provided, however, that,
so long as any shares of Series A Preferred Stock shall remain outstanding, the
Corporation shall not, without the requisite approval of the Holders of the
Series A Preferred Stock then outstanding, (a) take any of the actions described
in Section 7, or (b) enter into any agreement or arrangement with respect to any
other action which requires the approval of the Holders of the Series A
Preferred Stock then outstanding, unless conditioned upon receipt of the
requisite approval of the Holders of the Series A Preferred Stock.

                  Section 4. Liquidation Preference.

         Subject to applicable law, upon any liquidation, dissolution or
winding-up of the Corporation, whether voluntary or involuntary (a
"LIQUIDATION"), the Holders shall be entitled to receive out of the assets of
the Corporation, whether such assets are capital or surplus, for each share of
Series A Preferred Stock, an amount equal to the Stated Value plus all accrued
but unpaid dividends per share, whether declared or not, before any distribution
or payment shall be made to the holders of any Junior Securities, and if the
assets of the Corporation shall be insufficient to pay in full such amounts and
all amounts payable to holders of Parity Stock, if any, then, subject to
applicable law, the entire assets to be distributed to the Holders and the
holders of Parity Stock, if any, shall be distributed among the Holders and the
holders of Parity Stock, if any, ratably in accordance with the respective
amounts that would be payable on such shares if all amounts payable thereon were
paid in full. The Corporation shall mail written notice of any such Liquidation
to each Holder not less than 45 days prior to the payment date stated therein.

                  Section 5. Conversion.

                  (a) (i) Each share of Series A Preferred Stock is convertible
by the Holder thereof into shares of Common Stock (subject to adjustment as
provided in this Section 5) at the Conversion Ratio at the option of the Holder
at any time and from time to time. A Holder shall effect conversions by
surrendering the certificate or certificates representing the shares of Series A
Preferred Stock to be converted to the Corporation, together with the form of
conversion notice attached hereto as EXHIBIT A (the "CONVERSION NOTICE"). Each
Conversion Notice shall specify the number of shares of Series A Preferred Stock
to be converted and the date on which such conversion is to be effected, which
date may not be prior to the date on which the Holder delivers such Conversion
Notice (the "CONVERSION DATE"). If no Conversion Date is specified in a
Conversion Notice, the Conversion Date shall be deemed to be the date that the
Conversion Notice is deemed delivered pursuant to Section 5(i). Subject to
Section 5(b), each Conversion
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Notice, once delivered, shall be irrevocable. If the Holder is converting less
than all of the shares of Series A Preferred Stock represented by the
certificate or certificates tendered by the Holder with the Conversion Notice,
or if a conversion hereunder cannot be effected in full for any reason, the
Corporation shall promptly deliver to such Holder (in the manner and within the
time set forth in Section 5(b)) a certificate for such number of shares of
Series A Preferred Stock as have not been converted. Except as otherwise
provided in the Certificate of Incorporation or this Certificate of
Designations, on and after the effective date of a conversion, the Holder
entitled to receive Common Stock issuable upon such conversion shall be treated
for all purposes as the record holder of the shares of Common Stock issuable
upon conversion, and the Series A Preferred Stock so converted shall no longer
be deemed to be issued and outstanding.

                           (ii) Notwithstanding anything contained in the
Certificate of Incorporation or this Certificate of Designations to the
contrary, in no event shall the Corporation be obligated to issue any shares of
Common Stock upon conversion of a Holder's shares of Series A Preferred Stock
if, based upon the number of shares of Common Stock outstanding as at the
Commencement Date, such issuance would be in violation of Nasdaq Rule
4460(i)(1)(D) ("RULE 4460"), if then applicable; provided, however, that, in
such event, the Corporation shall be obligated to (A) deliver (in the manner and
within the time set forth in Section 5(b)) the maximum number of shares of
Common Stock as would not be in violation of Rule 4460, (B) use its reasonable
best efforts to take all such actions as shall be necessary or appropriate to
promptly cause such issuance not to be in violation of Rule 4460, and (C)
deliver the remaining shares of Common Stock (in the manner and within the time
set forth in Section 5(b)) as soon as it is possible to do so other than in
violation of Rule 4460; provided further, however, that in the case of clauses
(A) and (C) above, each such issuance shall be distributed ratably among the
Holders based upon the number of shares of Series A Preferred Stock each Holder
has requested to be converted into Common Stock.

                  (b) Not later than three Trading Days after a Conversion Date,
the Corporation shall deliver to the converting Holder (i) one or more
certificates representing the number of shares of Common Stock being issued upon
the conversion of shares of Series A Preferred Stock, (ii) one or more
certificates representing the number of shares of Series A Preferred Stock not
converted, (iii) a bank check in the amount of accrued and unpaid dividends (if
the Corporation has elected or is required hereunder to pay accrued dividends in
cash), and (iv) if the Corporation has elected and is permitted hereunder
(notwithstanding any applicable notice period) to pay accrued dividends in
shares of Common Stock, one or more certificates representing such number of
shares of Common Stock as are issuable on account of accrued dividends
determined in accordance with Section 2(a); provided, however, that the
Corporation shall not be obligated to issue certificates evidencing the shares
of Common Stock issuable upon conversion of any shares of Series A Preferred
Stock until certificates evidencing such shares of Series A Preferred Stock are
either delivered for conversion to the Corporation or, if so directed by the
Corporation, to any transfer agent for the Series A Preferred Stock or Common
Stock, or the Holder of such Series A Preferred Stock certifies to the
Corporation and, if required, any such transfer agent that such certificates
have been lost, stolen or destroyed and provides a bond (or other adequate
security) reasonably satisfactory to the Corporation and any such transfer agent
to indemnify and hold harmless the Corporation and any such transfer agent from
any loss incurred by it in connection therewith. The Corporation shall, upon
request of the Holder, use its reasonable best efforts to deliver any
certificate or certificates required to be delivered by the
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Corporation under this Section 5(b) electronically through the Depository Trust
Corporation or another established clearing corporation performing similar
functions. If in the case of any Conversion Notice such certificate or
certificates, including for purposes hereof, any shares of Common Stock to be
issued on the Conversion Date on account of accrued but unpaid dividends
hereunder, are not delivered to or as directed by the applicable Holder by the
close of business on the third Trading Day after the Conversion Date, the Holder
shall be entitled by written notice to the Corporation at any time on or before
its receipt of such certificate or certificates thereafter, to rescind such
conversion, in which event the Corporation shall immediately return the
certificates representing the shares of Series A Preferred Stock tendered to it
for conversion and thereupon the Holder shall no longer be treated as a record
holder of the shares of Common Stock issuable upon conversion.

                  (c) (i) The conversion price for each share of Series A
Preferred Stock (the "CONVERSION PRICE") on any Conversion Date shall be equal
to $37.50; provided, however, that (A) if on the first anniversary of the
Commencement Date (the "ONE YEAR DATE") the Thirty Day Average Market Price of
the Common Stock (the "ONE YEAR RESET PRICE") is less than the then effective
Conversion Price, then on and after the One Year Date the Conversion Price shall
be equal to the One Year Reset Price, (B) if on the second anniversary of the
Commencement Date (the "TWO YEAR DATE") the Thirty Day Average Market Price of
the Common Stock (the "TWO YEAR RESET PRICE") is less than the then effective
Conversion Price, then on and after the Two Year Date the Conversion Price shall
be equal to the Two Year Reset Price, and (C) if on the third anniversary of the
Commencement Date (the "THREE YEAR DATE") the Thirty Day Average Market Price of
the Common Stock (the "THREE YEAR RESET PRICE") is less than the then effective
Conversion Price, then on and after the Three Year Date the Conversion Price
shall be equal to 95% of the Three Year Reset Price. The Conversion Price
determined in accordance with this Section 5(c)(i) shall be subject to further
adjustment as set forth in Sections 5(c)(ii), 5(c)(iii) and 5(c)(iv).

                           (ii) If the Corporation, at any time after the
Commencement Date, shall (A) pay a stock dividend or otherwise make a
distribution or distributions on shares of its Common Stock payable in shares of
Common Stock, (B) subdivide any outstanding shares of Common Stock into a larger
number of shares, (C) combine any outstanding shares of Common Stock into a
smaller number of shares, or (D) issue by reclassification of shares of Common
Stock any shares of capital stock of the Corporation, then the Conversion Price
shall be adjusted by multiplying the Conversion Price then in effect by a
fraction, the numerator of which shall be the number of shares of Common Stock
outstanding before such event, and the denominator of which shall be the number
of shares of Common Stock outstanding after such event. Such adjustment shall be
made each time any such dividend, distribution, subdivision, combination or
reclassification is made and shall become effective (X) immediately after the
record date for the determination of stockholders entitled to receive such
dividend or distribution, or (Y) immediately after the effective date in the
case of a subdivision, combination or re-classification.

                           (iii) If the Corporation, at any time after the
Commencement Date, shall distribute to all holders of Common Stock as a class
(and not to Holders) evidences of its indebtedness or assets, then in each such
case the Conversion Price at which each share of Series A Preferred Stock shall
thereafter be convertible shall be adjusted by multiplying the Conversion Price
in effect immediately prior to the record date fixed for determination of
stockholders
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entitled to receive such distribution by a fraction, the denominator of which
shall be the Five Day Average Market Price of Common Stock determined as of the
record date mentioned above, and the numerator of which shall be such Five Day
Average Market Price of the Common Stock on such record date less the then fair
market value at such record date of the portion of such assets or the value of
such evidence of indebtedness so distributed applicable to one outstanding share
of Common Stock as determined by the Board of Directors in good faith; provided,
however, that in the event of a distribution exceeding 10% of the net assets of
the Corporation, such fair market value shall be determined by a nationally
recognized or major regional investment banking firm or firm of independent
certified public accountants of recognized standing (which may be the firm that
regularly examines the financial statements of the Corporation) (an "APPRAISER")
selected in good faith by the Corporation and reasonably acceptable to the
Holders of a majority in interest of the shares of Series A Preferred Stock then
outstanding. Such adjustment shall be made each time any such distribution is
made and shall become effective immediately after the record date mentioned
above.

                           (iv) (A) If the Corporation, at any time after the
Commencement Date, shall issue or sell any shares of Common Stock (other than
(I) in payment of a dividend upon, or upon the conversion of, shares of Series A
Preferred Stock, or (II) upon exercise or conversion of warrants, options or
convertible or exchangeable securities outstanding as of the Commencement Date)
without consideration or at a price per share that is less than the Five Day
Average Market Price in effect immediately prior to such issuance or sale, then
in each such case the Conversion Price, upon each such issuance or sale, shall
be lowered to that price determined by multiplying the Conversion Price then in
effect by a fraction, the numerator of which shall be the sum of the number of
shares of Common Stock outstanding immediately prior to such issuance or sale
plus the number of shares of Common Stock which the aggregate consideration, if
any, received by the Corporation for such additional shares of Common Stock so
issued or sold would purchase at the Five Day Average Market Price then in
effect, and the denominator of which shall be the number of shares of Common
Stock outstanding immediately prior to such issuance or sale plus the number of
such additional shares of Common Stock so issued or sold.

                                    (B) For purposes of this Section 5(c)(iv),
the issuance (or adjustment in exercise or purchase price) of any warrants,
options, subscriptions or other purchase rights with respect to shares of Common
Stock (other than to all holders of Common Stock as a class), and the issuance
(or adjustment in conversion price or exchange ratio) of any securities
convertible into or exchangeable for shares of Common Stock (or the issuance or
adjustment in exercise or purchase price of any warrants, options, subscriptions
or other purchase rights with respect to such convertible or exchangeable
securities) shall be deemed to be an issuance at such time of shares of Common
Stock, and shall be subject to the provisions of Section 5(c)(iv)(A), if the
Five Day Average Market Price then in effect is greater than an amount equal to
(I) the sum of the aggregate consideration, if any, received by the Corporation
for the issuance of such warrants, options, subscriptions, other purchase rights
and/or convertible or exchangeable securities, plus the minimum amount of
consideration, if any, payable to the Corporation upon the exercise, purchase,
conversion or exchange thereof, divided by (II) the aggregate number of shares
of Common Stock that would be issued if all such warrants, options,
subscriptions, other purchase rights and/or convertible and exchangeable
securities were exercised, purchased, converted or exchanged, in each case
determined as of the date of issuance or sale (or adjustment in exercise,
purchase or conversion price or exchange ratio), without
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giving effect to any possible future upward price adjustments or rate
adjustments. For purposes of this Section 5(c)(iv), if a part or all of the
consideration received by the Corporation in connection with such issuance or
sale shall consist of property other than cash, then the fair market value of
such property shall be determined by the Board of Directors in good faith;
provided, however, that in the event the aggregate number of shares of Common
Stock subject to issuance or sale exceeds 10% of the shares of Common Stock
outstanding immediately prior to the issuance or sale of such warrants, options,
subscriptions, other purchase rights and/or convertible or exchangeable
securities, then the fair market value of such property shall be determined by
an Appraiser.

                           (v) All calculations under this Section 5 shall be
made to the nearest whole cent or the nearest 1/100th of a share, as the case
may be.

                           (vi) Whenever the Conversion Price is adjusted
pursuant to this Section 5(c), the Corporation shall promptly give notice to
each Holder, which notice shall set forth the Conversion Price after such
adjustment and a brief statement of the facts requiring such adjustment.

                           (vii) If:

                                    (A) the Corporation shall declare a dividend
(or any other distribution) on its Common Stock;

                                    (B) the Corporation shall declare a special
non-recurring cash dividend on its Common Stock;

                                    (C) the Corporation shall authorize the
granting to all holders of the Common Stock, as a class, rights or warrants to
subscribe for or purchase any shares of capital stock of any class or of any
rights;

                                    (D) the approval of any stockholders of the
Corporation shall be required in connection with any reclassification of the
Common Stock of the Corporation, any consolidation or merger to which the
Corporation is a party, or any sale or transfer of all or substantially all of
the assets of the Corporation; or

                                    (E) the Corporation shall authorize the
voluntary or involuntary dissolution, liquidation or winding up of the affairs
of the Corporation;

then the Corporation shall cause to be filed at each office or agency maintained
for the purpose of conversion and transfer of Series A Preferred Stock, and
shall cause to be mailed to each of the Holders at their last addresses as they
shall appear upon the stock books of the Corporation, at least 30 calendar days
prior to the applicable record or effective date hereinafter specified, a notice
stating (I) the date on which a record is to be taken for the purpose of such
dividend, distribution, redemption, rights or warrants, or if a record is not to
be taken, the date as of which the holders of Common Stock of record to be
entitled to such dividend, distribution, redemption, rights or warrants are to
be determined, or (II) the date on which such reclassification, consolidation,
merger, sale or transfer is expected by the Corporation to become effective or
close, and the date as of which it is expected that holders of Common Stock of
record shall be
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entitled to exchange their shares of Common Stock for securities, cash or other
property deliverable upon such reclassification, consolidation, merger, sale or
transfer.

                  (d) If at any time conditions shall arise by reason of action
taken by the Corporation which in the opinion of the Board of Directors are not
adequately covered by the other provisions hereof and which would materially and
adversely affect the rights of the Holders (different than or distinguished from
the effect generally on rights of holders of any class of the Corporation's
capital stock), or if at any time any such conditions are expected by the
Corporation to arise by reason of any action contemplated by the Corporation,
the Corporation shall mail a written notice briefly describing the action
contemplated and the material adverse effects of such action on the rights of
the Holders at least 30 calendar days prior to the effective date of such
action, and an Appraiser selected by the Corporation and reasonably acceptable
to the Holders of a majority in interest of the Series A Preferred Stock then
outstanding shall give its opinion as to the adjustment, if any (not
inconsistent with the standards established in this Section 5), of the
Conversion Price (including, if necessary, any adjustment as to the securities
into which shares of Series A Preferred Stock may thereafter be convertible) and
any distribution which is or would be required to preserve without diluting the
rights of the Holders. To the extent permitted by applicable law and stock
exchange or Nasdaq rules, the Corporation shall make the adjustment recommended
forthwith upon the receipt of such opinion or the taking of any such action
contemplated, as the case may be; provided, however, that no such adjustment of
the Conversion Price shall be made which in the opinion of the Appraiser would
result in an increase of the Conversion Price to more than the Conversion Price
then in effect.

                  (e) The Corporation shall at all times reserve and keep
available out of its authorized and unissued Common Stock, solely for the
purpose of issuance in payment of dividends upon, and upon conversion of, the
Series A Preferred Stock as herein provided, free from preemptive rights or any
other actual or contingent purchase rights of Persons other than the Holders (in
their capacity as Holders), not less than the number of shares of Common Stock
as shall be issuable (taking into account the adjustments and restrictions of
Section 5(c)) in payment of dividends upon, or upon the conversion of, all
outstanding shares of Series A Preferred Stock assuming the payment of all
future dividends in shares of Common Stock in accordance with the terms hereof.
All shares of Common Stock that shall be so issuable shall, upon issue, be duly
authorized, validly issued and fully paid and non-assessable. At such time as
the Corporation would be, if a notice of conversion were to be delivered on such
date, precluded from converting the then outstanding Series A Preferred Stock by
reason of an insufficient number of authorized shares of Common Stock then being
authorized for issuance, the Corporation shall promptly prepare and mail to the
shareholders of the Corporation proxy materials requesting authorization to
amend the Corporation's Certificate of Incorporation to increase the number of
shares of Common Stock which the Corporation is authorized to issue to at least
a number of shares equal to the sum of (i) all shares of Common Stock then
outstanding, (ii) the number of shares of Common Stock issuable on account of
all outstanding warrants, options and convertible securities (other than the
Series A Preferred Stock) and on account of all shares reserved under any stock
option, stock purchase or similar plan or agreement, and (iii) the number of
shares of Common Stock as would then be issuable in payment of dividends upon,
and upon conversion in full of, the Series A Preferred Stock, assuming the
payment of all future dividends in shares of Common Stock in accordance with the
terms hereof. In connection therewith, the Corporation shall use reasonable
efforts to cause its Board of Directors to (i) adopt
<PAGE>   11
                                      -11-

proper resolutions authorizing such increase, (ii) recommend to and otherwise
use its reasonable best efforts to promptly and duly obtain shareholder approval
to carry out such resolutions (and hold a special meeting of the shareholders no
later than the 60th day after delivery of the proxy materials to the
shareholders relating to such meeting), and (iii) within five Trading Days of
obtaining such shareholder authorization, file an appropriate amendment to the
Corporation's Certificate of Incorporation to evidence such increase.

                  (f) Upon a conversion hereunder, the Corporation shall not be
required to issue certificates representing fractions of shares of Common Stock,
but may, to the extent permitted by applicable law, make a cash payment in
respect of any final fraction of a share based on the Five Day Average Market
Price as at the applicable Conversion Date.

                  (g) The issuance of certificates for shares of Common Stock
upon conversion of Series A Preferred Stock shall be made without charge to the
Holders thereof for any documentary stamp or similar taxes that may be payable
in respect of the issue or delivery of such certificates; provided, however,
that the Corporation shall not be required to pay any tax that may be payable in
respect of any transfer involved in the issuance and delivery of any such
certificate upon conversion in a name other than that of the Holder of such
shares of Series A Preferred Stock so converted, and that the Corporation shall
not be required to issue or deliver such certificates unless or until the Person
or Persons requesting the issuance thereof shall have paid to the Corporation
the amount of any such tax or shall have established to the satisfaction of the
Corporation that any such tax has been paid.

                  (h) Shares of Series A Preferred Stock converted into Common
Stock shall be canceled and shall have the status of authorized but unissued
shares of undesignated Preferred Stock.

                  (i) Except as may otherwise be required by applicable law, any
and all notices or other communications or deliveries to be provided by the
Holders hereunder, including, without limitation, any Conversion Notice, shall
be in writing and delivered personally, transmitted by facsimile, sent by a
nationally recognized overnight courier service or sent by certified or
registered mail, postage prepaid, addressed to the attention of the President of
the Corporation, with a copy to the Corporation's General Counsel (provided that
the failure to send a copy of such notice to the Corporation's General Counsel
shall not affect the validity of such notice), at the facsimile telephone number
or address of the principal place of business of the Corporation as set forth in
the Purchase Agreement, or at such other facsimile number or address as the
Corporation may notify the Holders in writing from time to time. Except as
otherwise specifically provided herein, any and all notices or other
communications or deliveries to be provided by the Corporation hereunder shall
be delivered in accordance with the provisions of the Purchase Agreement and
deemed given on the date or time provided therein.

                  Section 6. Optional Conversion. If at any time (the "225%
DATE") after the One Year Date (a) the Per Share Market Value for at least 30
consecutive Trading Days (provided, however, that, for purposes of such
calculation, at the option of the Corporation, any Trading Day during such
30-Trading-Day period on which a Holder sets the last closing bid price on the
Common Stock shall not be used in such calculation, in which case the first
Trading Day preceding such 30-Trading-Day period on which no Holder set the last
closing bid price on the
<PAGE>   12
                                      -12-

Common Stock shall be used for determining such calculation) is greater than
225% of the then effective Conversion Price (as adjusted in accordance with
Section 5(c)), and (b) the average daily trading volume of the Common Stock on
the Nasdaq National Market (or such other stock exchange or quotation system on
which the shares of Common Stock are listed or quoted) for such 30 consecutive
Trading Days exceeds 100,000 shares (as adjusted in accordance with Section
5(c)), then the Corporation shall, at its option, have the right to cause the
conversion of all, but not less than all, of the then outstanding shares of
Series A Preferred Stock into Common Stock in accordance with the terms of this
Certificate of Designations at the Conversion Price in effect on the date of the
225% Conversion Notice. If the Corporation elects to cause such a conversion, it
shall, within 15 days after the 225% Date, give written notice (the "225%
CONVERSION NOTICE") to the Holders of its intent to cause the conversion of the
Series A Preferred Stock on the date which is 30 days subsequent to the date of
the 225% Conversion Notice (the "225% CONVERSION DATE"); provided, however, that
no such conversion shall be permitted unless at the time of the delivery of the
225% Conversion Notice and on the 225% Conversion Date, (x) the shares of Common
Stock which would be issuable upon conversion of the Series A Preferred Stock
are designated for quotation or listed for trading on the Nasdaq National
Market, the New York Stock Exchange or the American Stock Exchange, and (y) the
Corporation has duly reserved for issuance the shares of Common Stock which
would be issuable upon such conversion.

                  Section 7. Protective Provisions. So long as any shares of
Series A Preferred Stock shall remain outstanding, except as otherwise provided
herein or by applicable law, the Corporation shall not, without first obtaining
the approval of the Holders of at least two-thirds of the then outstanding
shares of Series A Preferred Stock:

                  (a) alter or change the rights, preferences or privileges of
the Series A Preferred Stock so as to affect adversely the Series A Preferred
Stock as a class; provided, however, that neither the designation, creation or
issuance of any Junior Stock or Parity Stock shall be deemed to affect adversely
the Series A Preferred Stock as a class;

                  (b) create any new class or series of capital stock having a
preference over the Series A Preferred Stock as to redemption, conversion, the
payment of dividends or distribution of assets upon a Liquidation Event or any
other liquidation, dissolution or winding up of the Corporation;

                  (c) increase the authorized number of shares of Series A
Preferred Stock; or

                  (d) issue any shares of Series A Preferred Stock.

                  Section 8. Definitions. For the purposes hereof, the following
terms shall have the following meanings:

                  "APPRAISER" shall have the meaning set forth in Section
5(c)(iii).

                  "CERTIFICATE OF INCORPORATION" shall have the meaning set
forth in the resolution creating the Series A Preferred Stock.

                  "COMMENCEMENT DATE" means June 15, 2000.
<PAGE>   13
                                      -13-

                  "COMMON STOCK" means the common stock, $.01 par value per
share, of the Corporation, and any stock of any other class into which such
shares may hereafter have been reclassified or changed.

                  "COMMON STOCK DIVIDEND NOTICE" shall have the meaning set
forth in Section 2(a)(i).

                  "CONVERSION DATE" shall have the meaning set forth in Section
5(a)(i).

                  "CONVERSION NOTICE" shall have the meaning set forth in
Section 5(a)(i).

                  "CONVERSION PRICE" shall have the meaning set forth in Section
5(c)(i).

                  "CONVERSION RATIO" with respect to a share of Series A
Preferred Stock means, at any time, a fraction, the numerator of which is the
Stated Value of such share, and the denominator of which is the Conversion Price
as at such time.

                  "CORPORATION" shall have the meaning set forth in the
introduction to this Certificate of Designations.

                  "DIVIDEND PAYMENT DATE" shall mean March 31, June 30,
September 30 and December 31 of each year, commencing on September 30, 2000, and
each Conversion Date.

                  "FIVE DAY AVERAGE MARKET PRICE" as at any date shall mean the
average Per Share Market Value for the five Trading Days immediately preceding,
but not including, such date; provided, however, that, at the option of the
Corporation, any Trading Day during such five-Trading-Day period on which a
Holder sets the last closing bid price on the Common Stock shall not be used for
determining the Five Day Average Market Price, in which case the first Trading
Day preceding such five-Trading-Day period on which no Holder set the last
closing bid price on the Common Stock shall be used for determining the Five Day
Average Market Price.

                  "HOLDER" or "HOLDERS" shall have the meaning set forth in
Section 1.

                  "JUNIOR SECURITIES" means the Common Stock and all other
equity securities of the Corporation, other than Series A Preferred Stock and
Parity Stock, if any.

                  "LIQUIDATION" shall have the meaning set forth in Section 4.

                  "ONE YEAR DATE" shall have the meaning set forth in Section
5(c)(i).

                  "ONE YEAR RESET PRICE" shall have the meaning set forth in
Section 5(c)(i).

                  "PARITY STOCK" means any capital stock of the Corporation that
ranks on parity with the Series A Preferred Stock as to redemption, conversion,
the payment of dividends or distribution of assets upon a Liquidation Event or
any other liquidation, dissolution or winding up of the Corporation.
<PAGE>   14
                                      -14-

                  "PER SHARE MARKET VALUE" as at any particular date means (a)
the closing bid price per share of the Common Stock on such date on the Nasdaq
National Market or other principal stock exchange or quotation system on which
the Common Stock is then listed or quoted or, if there is no such price as at
such date, then the closing bid price on such exchange or quotation system as at
the date nearest preceding such date, or (b) if the Common Stock is not listed
or quoted then on the Nasdaq National Market or any other national securities
exchange or quotation system, the closing bid price for a share of Common Stock
in the over-the-counter market, as reported by the OTC Bulletin Board or in the
National Quotation Bureau Incorporated (or any similar organization or agency
succeeding to its functions of reporting prices) as at the close of business on
such date, or (c) if the Common Stock is not then reported by the National
Quotation Bureau Incorporated (or any similar organization or agency succeeding
to its functions of reporting prices), then the average of the "Pink Sheet" bid
quotes for the relevant day, as determined in good faith by the Holder, or (d)
if the Common Stock is not then publicly traded, the fair market value of a
share of Common Stock on such date as determined by an Appraiser selected in
good faith by the Corporation and reasonably acceptable to Holders of a majority
in interest of the shares of the Series A Preferred Stock then outstanding.

                  "PERSON" means an individual or corporation, partnership,
trust, incorporated or unincorporated association, joint venture, limited
liability company, joint stock company, government (or an agency or subdivision
thereof) or other entity of any kind.

                  "PURCHASE AGREEMENT" means the Purchase Agreement, dated as of
June 15, 2000, by and between the Corporation and PSINet Inc., a New York
corporation, a copy of which is available for inspection at the principal
corporate office of the Corporation.

                  "REGISTRATION RIGHTS AGREEMENT" means the Registration Rights
Agreement, dated as of June 15, 2000 by and among the Corporation and the
original Holders of the Series A Preferred Stock, a copy of which is available
for inspection at the principal corporate office of the Corporation.

                  "RULE 4460" shall have the meaning set forth in Section
5(a)(ii).

                  "SECURITIES ACT" means the Securities Act of 1933, as amended.

                  "SERIES A PREFERRED STOCK" shall have the meaning set forth in
Section 1.

                  "SERIES A PREFERRED STOCK DIRECTORS" shall have the meaning
set forth in Section 2(a)(ii).

                  "STATED VALUE" shall have the meaning set forth in Section 1.

                  "TRADING DAY" means (a) a day on which the Common Stock is
traded on the Nasdaq National Market or other principal stock exchange or
quotation system on which the Common Stock is then listed or quoted, or (b) if
the Common Stock is not listed or quoted on the Nasdaq National Market or any
other national securities exchange or quotation system, a day on which the
Common Stock is traded in the over-the-counter market, as reported by the OTC
Bulletin Board, or (c) if the Common Stock is not quoted on the OTC Bulletin
Board, a day on which the Common Stock is quoted in the over-the-counter market
as reported by the National
<PAGE>   15
                                      -15-

Quotation Bureau Incorporated (or any similar organization or agency succeeding
to its functions of reporting prices).

                  "THREE YEAR DATE" shall have the meaning set forth in Section
5(c)(i).

                  "THREE YEAR RESET PRICE" shall have the meaning set forth in
Section 5(c)(i).

                  "TWO YEAR DATE" shall have the meaning set forth in Section
5(c)(i).

                  "TWO YEAR RESET PRICE" shall have the meaning set forth in
Section 5(c)(i).

                  "225% DATE" shall have the meaning set forth in Section 6.

                  "225% CONVERSION DATE" shall have the meaning set forth in
Section 6.

                  "225% CONVERSION NOTICE" shall have the meaning set forth in
Section 6.

                  Section 9. Tax Withholding. Notwithstanding any provision
hereof to the contrary, all payments, distributions or transfers in respect of
the Series A Preferred Stock shall be subject to such withholdings as may be
required by applicable law.
<PAGE>   16
                                      -16-

         IN WITNESS WHEREOF, Xpedior Incorporated has caused this Certificate to
be executed by David N. Campbell, its President and Chief Executive Officer, as
of this ___ day of _______, 2000.

                                   XPEDIOR INCORPORATED

                                   By:
                                      --------------------
                                      Name:
                                      Title:
<PAGE>   17
                                    EXHIBIT A

                              NOTICE OF CONVERSION
                            AT THE ELECTION OF HOLDER

(To be executed by the registered Holder
in order to convert shares of Series A 8-1/2%
Cumulative Convertible Preferred Stock)

The undersigned hereby elects to convert the number of shares of Series A 8-1/2%
Cumulative Convertible Preferred Stock of Xpedior Incorporated (the
"CORPORATION") indicated below, into the number of shares of the Corporation's
common stock, par value $.01 per share (the "COMMON STOCK"), indicated below, as
of the date written below. If shares are to be issued in the name of a person
other than the undersigned, the undersigned will pay all transfer taxes payable
with respect thereto, if any, and is delivering herewith such certificates and
opinions as reasonably requested by the Corporation in connection therewith. No
fee will be charged to the Holder for any conversion, except for such transfer
taxes, if any.

Conversion calculations:

--------------------------------------------------------------------------------
                            Date to Effect Conversion

--------------------------------------------------------------------------------
Number of shares of Series A 8-1/2% Cumulative Convertible Preferred Stock to be
                                    Converted

--------------------------------------------------------------------------------
                  Number of shares of Common Stock to be Issued

--------------------------------------------------------------------------------
                           Applicable Conversion Price

                                        ----------------------------------------
                                        Signature

                                        ----------------------------------------
                                        Name

                                        ----------------------------------------
                                        Address
<PAGE>   18
                                   CERTIFICATE
                                     OF THE
                            DESIGNATIONS, PREFERENCES
                      AND RELATIVE, PARTICIPATING, OPTIONAL
                          AND OTHER SPECIAL RIGHTS AND
                  QUALIFICATIONS, LIMITATIONS AND RESTRICTIONS
                                     OF THE
             SERIES A 8-1/2% CUMULATIVE CONVERTIBLE PREFERRED STOCK
                                       OF
                              XPEDIOR INCORPORATED

                                    FILED BY:

                                  Ropes & Gray
                             One International Place
                           Boston, Massachusetts 02110<PAGE>   1

                                                                    EXHIBIT 10.1

                               PURCHASE AGREEMENT

                            DATED AS OF JUNE 15, 2000

                                     BETWEEN

                                   PSINET INC.

                                       AND

                              XPEDIOR INCORPORATED
<PAGE>   2
                                TABLE OF CONTENTS
<TABLE>
<CAPTION>
                                                                                    PAGE
<S>                                                                                 <C>
     ARTICLE I Purchase and Sale ................................................      1

     Section 1.1  Purchase and Sale .............................................      1
     Section 1.2  Preferred Stock ...............................................      1
     Section 1.3  Closing .......................................................      1
     Section 1.4  Deliveries at Closing .........................................      1

     ARTICLE II Representations and Warranties of Xpedior .......................      2

     Section 2.1  Organization and Qualification ................................      2
     Section 2.2  Capitalization ................................................      2
     Section 2.3  Authority Relative to this Agreement and the Transactions .....      4
     Section 2.4  No Conflicts; Required Filings and Consents ...................      4
     Section 2.5  Reports and Financial Statements ..............................      5
     Section 2.6  Litigation ....................................................      6
     Section 2.7  Absence of Certain Changes or Events ..........................      6
     Section 2.8  Employee Benefit Plans ........................................      7
     Section 2.9  Labor Relations ...............................................      9
     Section 2.10 Taxes .........................................................     10
     Section 2.11 Compliance with Applicable Laws ...............................     10
     Section 2.12 Assets of Xpedior and Its Subsidiaries ........................     11
     Section 2.13 Material Contracts ............................................     11
     Section 2.14 Intellectual Property .........................................     12
     Section 2.15 Interested Party Transactions .................................     13
     Section 2.16 Environmental Matters .........................................     13
     Section 2.17 Restrictions on Business Activities ...........................     14
     Section 2.18 Certain Business Practices ....................................     14
     Section 2.19 Insurance .....................................................     15
     Section 2.20 Brokers; Expenses .............................................     15
     Section 2.21 Private Offering ..............................................     15
     Section 2.22 Investment Company ............................................     15

     ARTICLE III Representations and Warranties of PSINet .......................     15

     Section 3.1  Organization and Qualification ................................     15
     Section 3.2  Authority Relative to this Agreement ..........................     16
     Section 3.3  No Conflicts, Required Filings and Consents ...................     16
     Section 3.4  Brokers .......................................................     16
     Section 3.5  Investment Intent .............................................     16
     Section 3.6  Status ........................................................     17

     ARTICLE IV Covenants .......................................................     17

     Section 4.1  Access to Information .........................................     17
     Section 4.2  Furnishing of Information .....................................     17
     Section 4.3  Integration ...................................................     17
     Section 4.4  Adoption of Shareholder Rights Plan ...........................     18
     Section 4.5  Information Statement .........................................     18
</TABLE>

                                      -i-
<PAGE>   3
<TABLE>
<CAPTION>
<S>                                                                                 <C>
     Section 4.6  Repayment of Metamor Note .....................................     18
     Section 4.7  Transfer Restrictions .........................................     18
     Section 4.8  Acknowledgment of Dilution ....................................     19
     Section 4.9  Copies and Use of Disclosure Materials ........................     19
     Section 4.10 Increase in Authorized Shares .................................     20
     Section 4.11 Listing of Underlying Shares ..................................     20
     Section 4.12 Conversion Obligations of Xpedior .............................     20
     Section 4.13 Rights and Warrants ...........................................     20

     ARTICLE V General Provisions ...............................................     21

     Section 5.1  Survival of Representations, Warranties and Agreements ........     21
     Section 5.2  Notices .......................................................     21
     Section 5.3  Specific Performance ..........................................     22
     Section 5.4  Entire Agreement ..............................................     22
     Section 5.5  Assignments; Parties in Interest ..............................     22
     Section 5.6  Governing Law .................................................     22
     Section 5.7  Headings; Disclosure ..........................................     23
     Section 5.8  Certain Definitions and Rules of Construction .................     23
     Section 5.9  Counterparts ..................................................     26
     Section 5.10 Severability ..................................................     27
     Section 5.11 Fees and Expenses .............................................     27
     Section 5.12 Amendment .....................................................     27
     Section 5.13 Waiver ........................................................     27
</TABLE>

<TABLE>
<CAPTION>
<S>                   <C>
     Exhibit A        Convertible Note
     Exhibit B        Certificate of Designations
     Exhibit C        Registration Rights Agreement
     Exhibit D        Legal Opinion of Ropes & Gray
</TABLE>

                                      -ii-
<PAGE>   4
                               PURCHASE AGREEMENT

     This PURCHASE AGREEMENT (this "AGREEMENT"), dated as of June 15, 2000, is
entered into by and between PSINet INC., a New York corporation ("PSINET"), and
XPEDIOR INCORPORATED, a Delaware corporation ("XPEDIOR"). Capitalized terms used
in this Agreement and not defined in context shall have the meanings ascribed to
them in Section 5.8(a).

     WHEREAS, the respective Boards of Directors of PSINet and Xpedior have
approved the issuance and sale by Xpedior to PSINet of a Convertible Note, dated
as of the date hereof, in substantially the form attached hereto as EXHIBIT A
(the "CONVERTIBLE NOTE"), which is convertible into an aggregate of 1,000,000
shares of Xpedior's Series A 8-1/2% Cumulative Convertible Preferred Stock, par
value $0.01 per share (the "SERIES A PREFERRED Stock"), all upon the terms and
subject to the conditions set forth herein;

     NOW, THEREFORE, in consideration of the foregoing premises and the
representations, warranties and agreements contained herein and for other good
and valuable consideration, the receipt and adequacy of which are hereby
acknowledged, the parties hereto, intending to be legally bound, agree as
follows:

                                   ARTICLE I

                                PURCHASE AND SALE

     Section 1.1 Purchase and Sale. Upon and subject to the conditions of this
Agreement, Xpedior shall issue and sell to PSINet, and PSINet shall purchase
from Xpedior, the Convertible Note for a purchase price of $50,000,000 (the
"PURCHASE PRICE").

     Section 1.2 Preferred Stock. The Series A Preferred Stock into which the
Convertible Note is convertible shall have the powers, designations, preferences
and relative, participating, optional and other rights and qualifications,
limitations and restrictions as set forth in the Certificate of Designations in
substantially the form attached hereto as EXHIBIT B (the "CERTIFICATE OF
DESIGNATIONS").

     Section 1.3 Closing. The closing of the Transactions (the "CLOSING") shall
take place on June 15, 2000. The Closing shall be held at the offices of Nixon
Peabody LLP, 401 9th Street, N.W., Washington D.C., unless another place is
agreed to in writing by the parties hereto. The date on which the Closing occurs
is referred to herein as the "CLOSING DATE".

     Section 1.4 Deliveries at Closing. At the Closing, (a) Xpedior shall
deliver to PSINet (i) an executed copy of the Convertible Note, (ii) an executed
copy of the Registration Rights Agreement, dated as of the date hereof, by and
between Xpedior and PSINet, in substantially the form attached hereto as EXHIBIT
C (the "REGISTRATION RIGHTS AGREEMENT"), (iii) an executed copy of the legal
opinion, dated as of the date hereof, of Ropes & Gray, counsel to Xpedior, in
substantially the form attached hereto as EXHIBIT D, (iv) evidence, in a form
satisfactory to PSINet, that Xpedior has paid to Metamor Worldwide, Inc., a
Delaware corporation which owns a majority in interest of the outstanding
capital stock of Xpedior ("METAMOR"), prior to the Closing (except as otherwise
provided in Section 1.4(b)(i)), all accounts payable from Xpedior to Metamor
(the "METAMOR PAYABLE"), and (v) all other documents, instruments and writings
<PAGE>   5
required to have been delivered at or prior to the Closing by Xpedior pursuant
to this Agreement or that PSINet may reasonably request; and (b) PSINet shall
deliver to Xpedior (i) the Purchase Price, in immediately available funds, by
wire transfer to the account or accounts designated in writing by Xpedior for
such purpose at least three business days prior to the Closing Date (which
account or accounts shall, to the extent the Metamor Payable remains outstanding
as of the Closing, include an account designated by Metamor such that all or a
portion of the Purchase Price to be paid by PSINet shall be delivered to
Metamor, on Xpedior's behalf, in full satisfaction of the Metamor Payable), (ii)
an executed copy of the Registration Rights Agreement, and (iii) all other
documents, instruments and writings required to have been delivered at or prior
to the date hereof by PSINet pursuant to this Agreement or that Xpedior may
reasonably request.

                                   ARTICLE II

                    REPRESENTATIONS AND WARRANTIES OF XPEDIOR

     Xpedior represents and warrants to PSINet that, except as disclosed on the
Xpedior Disclosure Schedule which has been delivered to PSINet prior to the
execution of this Agreement (the "XPEDIOR DISCLOSURE SCHEDULE"):

     Section 2.1 Organization and Qualification. Xpedior is a corporation duly
incorporated, validly existing and in good standing under the laws of the State
of Delaware. Each of Xpedior's Subsidiaries is a corporation or limited
liability company duly organized, validly existing and, if applicable, in good
standing under the laws of the jurisdiction in which it was formed. Each of
Xpedior and its Subsidiaries has the requisite corporate power and authority to
carry on its business as it is now being conducted and is duly qualified or
licensed to do business, and, if applicable, is in good standing, in each
jurisdiction where the character of its properties owned or held under lease or
the nature of its activities makes such qualification or licensing necessary,
except where the failure to be so organized, qualified, licensed or in good
standing, or to have such power and authority, when taken together with all
other such failures would not have an Xpedior Material Adverse Effect. Xpedior
has heretofore made available to PSINet a complete and correct copy of the
certificate of incorporation, by-laws and other governing documents, each as
amended to the date hereof, of Xpedior and each of its Subsidiaries.

     Section 2.2 Capitalization.

         (a) The authorized capital stock of Xpedior consists of 100,000,000
shares of common stock, par value $.01 per share (the "COMMON STOCK"), and
5,000,000 shares of preferred stock, par value $0.01 per share (the "PREFERRED
STOCK"), of which 1,000,000 shares shall be designated as Series A 8-1/2%
Cumulative Convertible Preferred Stock, par value $0.01 per share, pursuant to
Section 1.2. As of June 1, 2000, (i) 50,000,000 shares of Common Stock were
issued and outstanding, all of which were duly authorized, validly issued, fully
paid and non-assessable, and 40,005,048 of which were owned beneficially and of
record by Metamor, (ii) an aggregate of 15,000,000 shares of Common Stock were
reserved for issuance under stock options issuable pursuant to Xpedior's Stock
Incentive Plan (the "STOCK OPTIONS"), and (iii) no shares of Preferred Stock
were issued or outstanding. As of May 31, 2000, there were

                                      -2-
<PAGE>   6
outstanding Stock Options to purchase 11,164,385 shares of Common Stock, none of
which will be subject to accelerated vesting or exercisability in connection
with the execution and delivery of this Agreement or the consummation of the
Transactions. No shares of capital stock of Xpedior or any of its Subsidiaries
have been issued between March 20, 2000 and the date hereof.

         (b) The Convertible Note has been duly authorized and, when issued in
accordance with this Agreement will be free and clear of any and all liens,
charges, claims, encumbrances, restrictions and rights of first refusal or
preemptive rights of any kind granted by or binding upon Xpedior (collectively,
"LIENS") other than restrictions imposed by federal and applicable state
securities laws. The Series A Preferred Stock into which the Convertible Note is
convertible, and the Common Stock issuable in payment of dividends upon, and
upon conversion of, the Series A Preferred Stock, has been duly authorized and,
when issued in accordance with the Convertible Note and the Certificate of
Designations, will be validly issued, fully paid and non-assessable, free and
clear of any and all Liens other than restrictions imposed by federal and
applicable state securities laws. Xpedior has an adequate reserve of Preferred
Stock and Common Stock to enable it to perform its conversion and other
obligations under this Agreement, the Convertible Note and the Certificate of
Designations, which number of reserved and available shares of Preferred Stock
and Common Stock is equal to, respectively, at least the number of shares of
Preferred Stock as is issuable upon conversion of the Convertible Note and the
number of shares of Common Stock as is issuable in payment of dividends upon,
and upon conversion in full of, the Series A Preferred Stock, assuming the
payment of all dividends in shares of Common Stock in accordance with the terms
of the Certificate of Designations.

         (c) Except for the Convertible Note to be issued in connection with
this Agreement, and except as set forth on the Xpedior Disclosure Schedule,
there are no preemptive or other outstanding rights, options, warrants,
conversion rights (including pursuant to convertible securities), stock
appreciation rights, redemption rights, repurchase rights, voting, buy-sell or
other agreements, arrangements, calls, commitments or rights of any kind
relating to the issued or unissued capital stock of Xpedior or any of its
Subsidiaries or obligating Xpedior or any of its Subsidiaries to issue or sell
any shares of capital stock of, or other equity interests in, Xpedior or any of
its Subsidiaries. All shares of capital stock of Xpedior and its Subsidiaries
subject to issuance pursuant to the Stock Options, upon issuance on the terms
and conditions specified in the instruments pursuant to which they are issuable,
will be duly authorized, validly issued, fully paid and non-assessable. Without
limiting the generality of the foregoing, neither Xpedior nor any of its
Subsidiaries has adopted a shareholder rights plan or similar plan or
arrangement. As of the date of this Agreement, there are no outstanding
contractual obligations of Xpedior or any of its Subsidiaries to repurchase,
redeem or otherwise acquire any shares of capital stock of Xpedior or any of its
Subsidiaries or to provide material funds to, or make any material investment
(in the form of a loan, capital contribution or otherwise) in, any Person except
as set forth on the Xpedior Disclosure Schedule. Except for the Registration
Rights Agreement or as set forth on the Xpedior Disclosure Schedule, neither
Xpedior nor any Person acting on its behalf has granted to any Person other than
PSINet the right to (i) require Xpedior to file a registration statement under
the Securities Act with respect to Common Stock or other securities of Xpedior
held by them, or which they have a right to acquire, other than such rights as
have heretofore been exercised and satisfied, or (ii) include any shares of
Common Stock or other securities of Xpedior held by them, or which they have a
right to acquire, in any registration statement filed by Xpedior.

                                      -3-
<PAGE>   7
         (d) Xpedior has taken action to cause Section 203 of the Delaware
General Corporation Law to be inapplicable to Xpedior. The consummation of the
Transactions will not cause PSINet to become an interested stockholder of
Xpedior for the purposes of Section 203 of the Delaware General Corporation Law.

     Section 2.3 Authority Relative to this Agreement and the Transactions.
Xpedior has all necessary power and authority to execute and deliver this
Agreement, the Convertible Note and the Registration Rights Agreement, to
perform its obligations hereunder and to consummate the Transactions. The
execution and delivery of this Agreement, the Convertible Note and the
Registration Rights Agreement, by Xpedior, and the consummation by Xpedior of
the Transactions, have been duly and validly authorized by all necessary
corporate action of the stockholders (subject to, with respect to the issuance
of the Series A Preferred Stock and the Common Stock issuable in payment of
dividends upon, and upon conversion of, the Series A Preferred Stock, compliance
with Section 4.5) and of the board of directors of Xpedior and no other
corporate or stockholder proceedings on the part of Xpedior are necessary to
authorize the execution and delivery of this Agreement, the Convertible Note and
the Registration Rights Agreement, or to consummate the Transactions. This
Agreement, the Convertible Note and the Registration Rights Agreement, have each
been duly and validly executed and delivered by Xpedior and, assuming the due
authorization, execution and delivery hereof by PSINet, if applicable,
constitutes a legal, valid and binding obligation of Xpedior, enforceable
against Xpedior in accordance with its terms.

     Section 2.4 No Conflicts; Required Filings and Consents.

         (a) Subject to, with respect to the issuance of the Series A Preferred
Stock and the Common Stock issuable in payment of dividends upon, and upon
conversion of, the Series A Preferred Stock, compliance with Section 4.5, the
execution and delivery of this Agreement, the Convertible Note and the
Registration Rights Agreement, by Xpedior do not, and the performance of this
Agreement and consummation of the Transactions by Xpedior will not, (i) conflict
with or violate the certificate of incorporation, by-laws or other governing
documents of Xpedior or any of its Subsidiaries, (ii) assuming the consents,
approvals, authorizations and waivers specified in Section 2.4(b) have been
received and any condition precedent to such consent, approval, authorization or
waiver has been satisfied, conflict with or violate any Law applicable to
Xpedior or any of its Subsidiaries or by which any property or asset of Xpedior
or any of its Subsidiaries is bound or affected, or (iii) result in any breach
of or constitute a default (or an event which with notice or lapse of time or
both would become a default) under, or give to others any right of termination,
amendment, acceleration or cancellation of, or result in the creation of a lien
or other encumbrance on any property or asset of Xpedior or any of its
Subsidiaries pursuant to, any contract, agreement, note, bond, mortgage,
indenture, credit agreement, lease, license, permit, franchise or other
instrument or obligation to which Xpedior or any of its Subsidiaries is a party
or by which Xpedior or any of its Subsidiaries or any property or asset of
Xpedior or any of its Subsidiaries is bound or affected, except in the case of
clauses (ii) and (iii) for any such conflicts, violations, breaches, defaults or
other occurrences of the type referred to above that would not have an Xpedior
Material Adverse Effect or would not prevent or materially delay the
consummation of the Transactions.

                                      -4-
<PAGE>   8
         (b) Subject to, with respect to the issuance of the Series A Preferred
Stock and the Common Stock issuable in payment of dividends upon, and upon
conversion of, the Series A Preferred Stock, compliance with Section 4.5, the
execution and delivery of this Agreement, the Convertible Note and the
Registration Rights Agreement, by Xpedior do not, and the performance of this
Agreement, the Convertible Note and the Registration Rights Agreement, and
consummation of the Transactions by Xpedior will not, require any consent,
approval, authorization, waiver or permit of, or filing with or notification to,
any governmental or regulatory authority, domestic, foreign or supranational (a
"GOVERNMENTAL ENTITY"), except for (i) filings pursuant to exemptions from the
Securities Act of 1933, as amended (the "SECURITIES ACT"), and applicable state
securities or "blue sky" laws ("BLUE SKY LAWS") in connection with the sale and
issuance of the Series A Preferred Stock, and (ii) filing and recordation of the
Certificate of Designations as required by the Delaware General Corporation Law,
except where failure to obtain such consents, approvals, authorizations or
permits, or to make such filings or notifications, would not have an Xpedior
Material Adverse Effect or would not prevent or materially delay the
consummation of the Transactions.

     Section 2.5 Reports and Financial Statements.

         (a) Xpedior has filed with the U.S. Securities and Exchange Commission
(the "SEC") all forms, reports, schedules, registration statements, definitive
proxy statements, information statements and other filings ("SEC REPORTS")
required to be filed by it with the SEC since December 1, 1999. As of their
respective dates, the SEC Reports complied as to form in all material respects
with the requirements of the Securities Exchange Act of 1934, as amended (the
"EXCHANGE ACT"), and the Securities Act, as the case may be, and the rules and
regulations of the SEC thereunder applicable to such SEC Reports. As of their
respective dates and as of the date any information from such SEC Reports has
been incorporated by reference, the SEC Reports did not contain any untrue
statement of a material fact or omit to state a material fact required to be
stated therein or necessary to make the statements therein, in light of the
circumstances under which they were made, not misleading. Xpedior has filed all
material contracts and agreements and other documents or instruments required to
be filed as exhibits to the SEC Reports.

         (b) The consolidated balance sheets of Xpedior as of December 31, 1999,
1998 and 1997 and the related consolidated statements of operations,
shareholders' equity and cash flows for the years ended December 31, 1999 and
1998 and the period from March 27, 1997 through December 31, 1997 (including the
related notes and schedules thereto) contained in Xpedior's Form 10-K for the
year ended December 31, 1999 (the "ANNUAL FINANCIAL STATEMENTS") present fairly,
in all material respects, the consolidated financial position and the
consolidated results of operations, retained earnings and cash flows of Xpedior
and its consolidated Subsidiaries as of the dates or for the periods presented
therein in conformity with United States generally accepted accounting
principles ("GAAP") applied on a consistent basis during the periods involved,
except as otherwise noted therein, including in the related notes.

         (c) The consolidated balance sheets and the related statements of
operations and cash flows (including, in each case, the related notes thereto)
contained in Xpedior's Form 10-Q for the quarterly period ended March 31, 2000
(the "QUARTERLY FINANCIAL STATEMENTS" and, together with the Annual Financial
Statements, the "FINANCIAL STATEMENTS") have been

                                      -5-
<PAGE>   9
prepared in accordance with the requirements for interim financial statements
contained in Regulation S-X, which do not require all the information and
footnotes necessary for a fair presentation of financial position, results of
operations and cash flows in conformity with GAAP. The Quarterly Financial
Statements reflect all adjustments necessary to present fairly in accordance
with GAAP (except as indicated), in all material respects, the consolidated
financial position, results of operations and cash flows of Xpedior and its
consolidated Subsidiaries for all periods presented therein.

         (d) Except as described in the SEC Reports or as set forth on the
Xpedior Disclosure Schedule, the adoption of SEC Staff Accounting Bulletin No.
101 (Revenue Recognition in Financial Statements) effective January 1, 2000 has
not adversely impacted, and will not adversely impact, in any material respect,
the amount or timing of revenue recognition by Xpedior or any of its
Subsidiaries as compared to their prior revenue recognition practices.

         (e) Except for those liabilities that are fully reflected or reserved
against on the Financial Statements or as set forth on the Xpedior Disclosure
Schedule, neither Xpedior nor any of its Subsidiaries has outstanding any
liability of any nature whatsoever (whether absolute, accrued, contingent or
otherwise and whether due or to become due) which would be required to be
reflected on a balance sheet or in the notes thereto prepared in accordance with
GAAP, except for liabilities and obligations which have been incurred since
March 31, 2000 in the ordinary course of business which are not material in
nature or amount.

     Section 2.6 Litigation. Except as disclosed in the SEC Reports or on the
Xpedior Disclosure Schedule, as of the date hereof, there is no civil, criminal
or administrative suit, action or proceeding pending or, to the knowledge of
Xpedior, threatened against or affecting Xpedior or any of its Subsidiaries that
would have an Xpedior Material Adverse Effect, nor is there any judgment,
decree, injunction or order of any Governmental Entity or arbitrator outstanding
against Xpedior or any of its Subsidiaries that would have an Xpedior Material
Adverse Effect.

     Section 2.7 Absence of Certain Changes or Events. Except as disclosed in
the SEC Reports or on the Xpedior Disclosure Schedule, or as permitted by
Section 4.1 for events after the date hereof, since March 31, 2000, Xpedior and
each of its Subsidiaries has conducted its business only in the ordinary course
and in a manner consistent with past practice, and since such date there has not
been (a) any Xpedior Material Adverse Effect, (b) any declaration, setting aside
or payment of any dividend or other distribution (whether in cash, stock or
property) with respect to any of Xpedior's or any of its Subsidiaries' capital
stock, or any redemption, purchase or other acquisition of any of its or any of
its Subsidiaries' capital stock, (c) any split, combination or reclassification
of any of Xpedior's or any of its Subsidiaries' capital stock or, except with
respect to the Stock Options, any issuance or the authorization of any issuance
of any other securities in respect of, in lieu of or in substitution for any
shares of any of Xpedior's or any of its Subsidiaries' capital stock, (d) any
granting by Xpedior or any of its Subsidiaries to any officer of Xpedior or any
of its Subsidiaries of any increase in compensation or any rights with respect
to compensation in the event of a "change in control" (however defined) of
Xpedior, except in the ordinary course of business consistent with prior
practice or as required under employment agreements in effect as of March 31,
2000, copies of which have been provided previously to PSINet, (e) any granting
by Xpedior or any of its Subsidiaries to any officer or any

                                      -6-
<PAGE>   10
group or class of employees of Xpedior of any increase in severance or
termination pay, except as required under employment, severance or termination
agreements or plans in effect as of March 31, 2000, copies of which have been
provided previously to PSINet, or as previously disclosed to PSINet, (f) any
entry by Xpedior or any of its Subsidiaries into any employment, severance or
termination agreement with any officer of Xpedior, or any increase in benefits
available under, or establishment of, any Benefit Plan, except in the ordinary
course of business consistent with past practice or as previously disclosed to
PSINet, or (g) any material change in accounting methods, principles or
practices by Xpedior, except insofar as may have been required by a change in
GAAP.

     Section 2.8 Employee Benefit Plans.

         (a) SCHEDULE 2.8 sets forth a complete and correct list of all existing
(i) "employee benefit plans" as defined in Section 3(3) of the Employee
Retirement Income Security Act of 1974, as amended ("ERISA"), and (ii) any other
material pension plans or employee benefit arrangements or payroll practices
(including severance pay, vacation pay, company awards, salary continuation for
disability, sick leave, deferred compensation, bonus or other incentive
compensation, stock option or stock purchase arrangements or policies)
maintained, or contributed to, by Xpedior, any of its Subsidiaries or any trade
or business (whether or not incorporated) which is treated with Xpedior or any
of its Subsidiaries as a single employer under Section 414(b), (c), (m) or (o)
of the Code (an "ERISA AFFILIATE") with respect to employees of Xpedior, any of
its Subsidiaries or any of their ERISA Affiliates (all such plans, arrangements
or practices, the "BENEFIT PLANS" and each such plan which is sponsored,
maintained or contributed to solely by one or more of Xpedior or its
Subsidiaries is referred to as an "XPEDIOR BENEFIT PLAN"). Each Xpedior Benefit
Plan is in writing and Xpedior has previously made available to PSINet a true
and complete copy of each existing Xpedior Benefit Plan document, including all
amendments thereto, and a true and complete copy of each material document, if
any, prepared in connection with each such Xpedior Benefit Plan, including (A) a
copy of each trust or other funding arrangement, (B) each summary plan
description and summary of material modifications, (C) the most recently filed
Form 5500, including all attachments thereto, (D) the most recently received IRS
determination letter, and (E) the most recently prepared actuarial report and
financial statement.

         (b) No "accumulated funding deficit" as defined in Section 412 of the
Code exists with respect to any Xpedior Benefit Plan, whether or not waived. No
"reportable event" within the meaning of Section 4043 of ERISA, and no event
described in Section 4062 or 4063 of ERISA, has occurred with respect to any
Xpedior Benefit Plan. Neither Xpedior nor any ERISA Affiliate of Xpedior has (i)
engaged in, or is a successor corporation or parent corporation to an entity
that has engaged in, a transaction described in Sections 4069 or 4212(c) of
ERISA, or (ii) incurred or reasonably expects to incur any material liability
under (A) Title IV of ERISA arising in connection with the termination of, or a
complete or partial withdrawal from, any plan covered or previously covered by
Title IV of ERISA, or (B) Section 4971 of the Code, that in either case could
become a liability of PSINet or any of its Affiliates after the Closing Date. As
of March 31, 2000, there was no material unfunded liability under any of the
Benefit Plans, computed using reasonable actuarial assumptions and determined as
if all benefits under such Benefit Plans were vested and payable as of such
date. No event has occurred since

                                      -7-
<PAGE>   11
March 31, 2000 that would cause Xpedior to believe that as of the date of this
Agreement there is any such material unfunded liability.

         (c) Each of the Xpedior Benefit Plans intended to qualify under Section
401(a) of the Code has received a favorable determination letter (or opinion
letter in the case of a prototype plan) from the Internal Revenue Service (the
"IRS") that such Benefit Plan is so qualified or is within the remedial
amendment period for applying for such a determination letter, and, except as
disclosed on the Xpedior Disclosure Schedule, nothing has occurred with respect
to the operation of any such Benefit Plan which, either individually or in the
aggregate, could cause the loss of such qualification or the imposition of any
material liability, penalty or tax under ERISA or the Code.

         (d) There has been no non-exempt prohibited transaction (within the
meaning of Section 406 of ERISA or Section 4975 of the Code) with respect to any
Xpedior Benefit Plan. None of Xpedior or its Subsidiaries is currently liable
for any excise tax or penalty in connection with any Benefit Plan arising under
the Code or ERISA, including but not limited to Sections 4971, 4972, 4975, 4979,
4980, 4980B and 4980D of the Code and Section 502 of ERISA, and, to the
knowledge of Xpedior, no fact or event exists which could give rise to any
liability except, in each case, for any such liability set forth on the Xpedior
Disclosure Schedule or that would not have an Xpedior Material Adverse Effect.

         (e) All contributions and premiums required by Law or by the terms of
any Xpedior Benefit Plan or any agreement relating thereto have been timely made
(without regard to any waivers granted with respect thereto) in all material
respects.

         (f) The liabilities of each Xpedior Benefit Plan that has been
terminated or otherwise wound up have been fully discharged in material
compliance with applicable Law.

         (g) There has been no violation of ERISA with respect to the filing of
applicable returns, reports, documents and notices regarding any of the Xpedior
Benefit Plans with the Secretary of Labor or the Secretary of the Treasury or
the furnishing of such notices or documents to the participants or beneficiaries
of the Xpedior Benefit Plans which, either individually or in the aggregate,
could result in a material liability to Xpedior or any of its Subsidiaries.

         (h) To the knowledge of Xpedior, there are no pending legal proceedings
which have been asserted or instituted against any of the Xpedior Benefit Plans
or their assets, Xpedior or any of its Subsidiaries, or the plan administrator
or any fiduciary of any of the Xpedior Benefit Plans with respect to the
operation of such plans (other than routine, uncontested benefits claims).

         (i) Each of the Xpedior Benefit Plans has been maintained, in
accordance with its terms and all provisions of applicable Laws except where
failure to do so would not, either individually or in the aggregate, have an
Xpedior Material Adverse Effect. All amendments and actions required to bring
each of the Xpedior Benefit Plans into conformity in all material respects with
all of the applicable provisions of ERISA and other applicable Laws

                                      -8-
<PAGE>   12
have been made or taken, except to the extent that such amendments or actions
are not required by Law to be made or taken until a date after the Closing Date.

         (j) None of Xpedior or its Subsidiaries maintains or has any liability
under any welfare benefit plan providing continuing benefits after the
termination of employment (other than as required by Section 4980B of the Code
and at the former employee's own expense). Except as set forth on the Xpedior
Disclosure Schedule, Xpedior and its Subsidiaries have complied in all material
respects with the notice and continuation requirements of Section 4980B of the
Code and the regulations thereunder. Other than money purchase pension plans,
none of Xpedior, its Subsidiaries and their ERISA Affiliates maintains, sponsors
or contributes to, or, to the knowledge of Xpedior, has ever maintained,
sponsored or contributed to, any benefit plan subject to Title IV of ERISA,
including but not limited to any multiple employer plan subject to Sections 4063
and 4064 of ERISA or any multiemployer plan as defined in Section 4001(a)(3) of
ERISA.

         (k) Neither the execution and delivery of this Agreement, nor the
consummation of the Transactions, will (i) result in any material payment
(including severance, unemployment compensation or golden parachute) becoming
due to any director, employee or independent contractor of Xpedior or any of its
Subsidiaries, (ii) materially increase any benefits otherwise payable under any
Xpedior Benefit Plan, or (iii) result in the acceleration of the time of payment
or vesting of any such benefits to any material extent other than vesting of the
Stock Options in accordance with their terms.

         (l) Xpedior and each of its Subsidiaries are in compliance in all
material respects with all applicable Laws and collective bargaining agreements
with respect to all benefit plans, contracts and arrangements covering non-U.S.
employees ("NON-U.S. XPEDIOR BENEFIT PLANS"). None of Xpedior and its
Subsidiaries have any material unfunded liabilities under any Non-U.S. Xpedior
Benefit Plan in violation of local Law or that would, if the plan were covered
by ERISA, violate the funding obligations prescribed by ERISA. All benefits
payable under each of the Non-U.S. Xpedior Benefit Plans are provided in
accordance with the terms of the governing provisions of the relevant Non-U.S.
Xpedior Benefit Plan. None of Xpedior and its Subsidiaries are aware of any
failure to comply with any applicable Law which would or might result in the
loss of tax approval or qualification of any Non-U.S. Xpedior Benefit Plan.

         (m) To the knowledge of Xpedior, all individuals providing services to
Xpedior and its Subsidiaries have been properly characterized and treated as
being either an employee or an independent contractor of such Person.

     Section 2.9 Labor Relations. There are no labor controversies pending or,
to Xpedior's knowledge, threatened with respect to Xpedior or any of its
Subsidiaries, and neither Xpedior nor any of its U.S. Subsidiaries is a party to
any collective bargaining agreement with any labor union or other representative
of employees. Except as set forth on the Xpedior Disclosure Schedule, no
non-U.S. Subsidiary of Xpedior is a party to any collective bargaining agreement
with any labor union or other representative of employees or any works' council
or similar entity under applicable Laws. To the knowledge of Xpedior, there is
no pending or threatened union organization activity by or among any of its or
any of its Subsidiaries'

                                      -9-
<PAGE>   13
employees. No independent contractors of the Company have asserted claims for
benefits or compensation under any Benefit Plans.

     Section 2.10 Taxes. Xpedior and each of its Subsidiaries have duly filed
all material federal, state, local and foreign income, franchise, excise, real
and personal property and other Tax returns and reports (including, but not
limited to, those filed on a consolidated, combined or unitary basis) required
to have been filed by Xpedior or any of its Subsidiaries prior to the date
hereof. All of the foregoing returns and reports are true and correct in all
material respects, and Xpedior and its Subsidiaries have paid or, prior to the
Closing Date will pay, all Taxes shown on such returns or reports as being due.
Xpedior and each of its Subsidiaries have paid and will pay all installments of
estimated taxes due on or before the Closing Date. Xpedior and each of its
Subsidiaries have paid or made adequate provision in accordance with GAAP in the
SEC Reports and Financial Statements for all Taxes payable in respect of all
periods ending on or prior to the date of this Agreement and will have paid or
provided for all Taxes payable in respect of all periods covered thereby. As of
the date hereof, all deficiencies proposed as a result of any audits have been
paid or settled. Xpedior and each of its Subsidiaries has paid, collected or
withheld, or caused to be paid, collected or withheld, all amounts of Tax
required to be paid, collected or withheld, other than such Taxes for which
adequate reserves in the SEC Reports or Financial Statements have been
established or which are being contested in good faith, except as would not have
an Xpedior Material Adverse Effect. There are no claims or assessments pending
against Xpedior or any of its Subsidiaries for any alleged deficiency in any
Tax, and neither Xpedior nor any of its Subsidiaries has been notified in
writing of any proposed Tax claims or assessments against Xpedior or any of its
Subsidiaries. Neither Xpedior nor any of its Subsidiaries has been a member of a
consolidated group filing a consolidated federal income Tax return (other than a
consolidated group of which Metamor is the common parent), or has any liability
for Taxes of any other Person (other than a member of the Metamor consolidated
group) arising from the application of Treasury Regulation Section 1.1502-6
promulgated under the Code (or any analogous Law). No consent under Section
341(f) of the Code has been filed with respect to Xpedior or any of its
Subsidiaries. Except as set forth on the Xpedior Disclosure Schedule, there is
no contract, agreement, plan or arrangement covering any Person that,
individually or collectively, could give rise to the payment of any amount that
would not be deductible by Xpedior or any of its Subsidiaries by reason of
Section 280G of the Code.

     Section 2.11 Compliance with Applicable Laws. Xpedior and each of its
Subsidiaries hold all permits, licenses, variances, exemptions, orders and
approvals of all Governmental Entities (the "PERMITS") necessary for them to
own, lease or operate their properties and assets and to carry on their
businesses substantially as now conducted or presently intended to be conducted,
except for such permits, licenses, variances, exemptions, orders and approvals
the failure of which to hold would not have an Xpedior Material Adverse Effect.
The Permits are valid and in full force and effect except as would not have an
Xpedior Material Adverse Effect. Except as set forth in the SEC Reports filed
prior to the date hereof, the businesses of each of Xpedior and each of its
Subsidiaries have not been, and are not being, conducted in violation of any
Permit or any Law, arbitration award, agency requirement, license or permit of
any Governmental Entity (a "GOVERNMENTAL REGULATION"), except for violations or
possible violations that would not have an Xpedior Material Adverse Effect or
prevent or materially burden or materially impair the ability of Xpedior to
consummate the Transactions. Except as set forth in the SEC Reports filed prior
to the date hereof, no material investigation or review by

                                      -10-
<PAGE>   14
any Governmental Entity with respect to Xpedior or any of its Subsidiaries is
pending or, to Xpedior's knowledge, threatened, nor has any Governmental Entity
indicated an intention to conduct any such investigation or review. No material
change is required in Xpedior's or any of its Subsidiaries' operations,
properties or procedures to comply with any Permit, Law or Governmental
Regulation, and Xpedior has not received any notice or communication of any
material noncompliance with any Permit or Governmental Regulation that has not
been cured as of the date hereof, except as would not have an Xpedior Material
Adverse Effect.

     Section 2.12 Assets of Xpedior and Its Subsidiaries. Xpedior and each of
its Subsidiaries has good and defensible title to all of its material properties
and assets, free and clear of all liens, charges and encumbrances, except liens
for Taxes not yet due and payable and such liens or other imperfections of title
that do not individually or in the aggregate constitute an Xpedior Material
Adverse Effect. All leases, easements, licenses, rights of way and other rights
pursuant to which Xpedior or any of its Subsidiaries lease from others or
otherwise have the right to use real or personal property, individually or in
the aggregate material to the business of Xpedior (the "PROPERTY RIGHTS"), are
valid and binding and are in full force and effect and enforceable against
Xpedior or its Subsidiaries and, to Xpedior's knowledge, the other parties
thereto, as applicable, in accordance with their respective terms, and there is
not, under any such Property Right, any existing default or event of default (or
event that with notice or lapse of time, or both, would constitute a default or
event of default), except where the lack of such validity and effectiveness or
the existence of such default or event of default does not and will not
constitute an Xpedior Material Adverse Effect. Xpedior has made available to
PSINet true and accurate copies of the documents creating or reflecting the
Property Rights. No consent of any Person is needed in order for each Property
Right to continue in full force and effect in accordance with its terms without
penalty, acceleration or rights of early termination by reason of the
consummation of the Transactions, except for consents the absence of which would
not have an Xpedior Material Adverse Effect. The tangible and intangible assets
owned or leased by Xpedior and its Subsidiaries are all of the assets used in
their respective businesses or necessary for them to conduct their respective
businesses as presently conducted or presently intended to be conducted. All
material items of tangible property used by Xpedior or its Subsidiaries in their
businesses are in operable condition and adequate for the purposes used (normal
wear and tear excepted).

     Section 2.13 Material Contracts. Neither Xpedior nor any of its
Subsidiaries is a party or is subject to any contract, note, bond, mortgage,
indenture, credit agreement, lease, license, agreement, understanding,
instrument, bid or proposal (excluding any contract or arrangement that is or is
associated with a Benefit Plan), or any amendment or modification thereto
(collectively, "CONTRACTS"), that is required to be described in or filed as an
exhibit to any SEC Report that is not so described in or filed as required by
the Securities Act or the Exchange Act, as the case may be. All Contracts to
which Xpedior or any of its Subsidiaries is a party, or by which any of them is
bound, are valid and binding and are in full force and effect and enforceable
against Xpedior, its Subsidiaries and, to the knowledge of Xpedior, the other
party or parties thereto in accordance with their respective terms, and no
consent of any Person is needed in order for each Contract to continue in full
force and effect in accordance with its terms without penalty, acceleration or
rights of early termination by reason of the consummation of the Transactions,
except for any failure to be in full force and effect or failure to obtain a
consent that would not, in the aggregate with all other such failures, have an
Xpedior Material Adverse

                                      -11-
<PAGE>   15
Effect. Neither Xpedior nor any of its Subsidiaries is in violation or breach
of, or default in any material respect under, any Contract to which it is a
party or by which it is bound, nor, to Xpedior's knowledge, is any other party
to any such Contract in violation or breach of or default in any material
respect under any such Contract.

     Section 2.14 Intellectual Property.

         (a) Except as set forth on the Xpedior Disclosure Schedule, Xpedior and
each of its Subsidiaries, directly or indirectly, own, license or otherwise have
legally enforceable rights to use, or can acquire on reasonable terms and
without material expense, all patents, trademarks, trade names, service marks,
copyrights and any applications therefor, technology, know-how, computer
software and applications and tangible or intangible proprietary information or
materials, that are material to and used in the businesses of Xpedior or any of
its Subsidiaries as presently conducted or presently intended to be conducted
(the "INTELLECTUAL PROPERTY RIGHTS").

         (b) In the case of Intellectual Property Rights owned by Xpedior or one
of its Subsidiaries, either Xpedior or such Subsidiary owns such Intellectual
Property Rights free and clear of any material liens, charges or encumbrances.
Xpedior or one of its Subsidiaries has an adequate right to the use of the
Intellectual Property Rights or the material covered thereby in connection with
the services or products in respect of which such Intellectual Property Rights
are being used. The manufacture, sale, licensing or use of any of the services
or products of Xpedior or any of its Subsidiaries as now manufactured, sold,
licensed or used, or proposed for manufacture, sale, licensing or use, by
Xpedior or any of its Subsidiaries in the ordinary course of Xpedior's business,
as presently conducted or presently intended to be conducted, does not infringe
on any copyright, patent, trade mark, service mark or trade secret of a third
party where such infringement could have an Xpedior Material Adverse Effect. The
use by Xpedior or any of its Subsidiaries of any trademarks, service marks,
trade names, trade secrets, copyrights, patents, technology or know-how or
applications used in the businesses of Xpedior or any of its Subsidiaries as
presently conducted or presently intended to be conducted does not infringe on
any other Person's trademarks, service marks, trade names, trade secrets,
copyrights, patents, technology or know-how or applications where such
infringement could have an Xpedior Material Adverse Effect. Except as set forth
on the Xpedior Disclosure Schedule, Xpedior has not received any information
challenging the ownership by Xpedior or any of its Subsidiaries, or the validity
of, any of the Intellectual Property Rights. All registered patents, trademarks,
service marks and copyrights held by Xpedior and its Subsidiaries are valid and
subsisting, except to the extent any failure to be valid and subsisting does not
constitute an Xpedior Material Adverse Effect. To the knowledge of Xpedior,
there is no material unauthorized use, infringement or misappropriation of any
of the Intellectual Property Rights by any third party, including any employee
or former employee of Xpedior or any of its Subsidiaries. Xpedior or one of its
Subsidiaries has valid, binding and enforceable agreements with each employee,
former employee and contractor who has or has had access to confidential or
proprietary intellectual property of Xpedior or any of its Subsidiaries pursuant
to which such Person is required to maintain the confidentiality of such
information for a reasonable period of time, or such agreements are not
necessary to adequately protect the interests of Xpedior or such Subsidiary. No
Intellectual Property Right is subject to any known outstanding decree, order,
judgment or

                                      -12-
<PAGE>   16
stipulation restricting in any manner the licensing thereof by Xpedior or any of
its Subsidiaries, except to the extent any such restriction does not constitute
an Xpedior Material Adverse Effect.

         (c) The computer systems, software, hardware, firmware, middleware and
other information technology (collectively, "INFORMATION TECHNOLOGY") of Xpedior
and each of its Subsidiaries are Year 2000 Ready, except as would not have an
Xpedior Material Adverse Effect, and none of Xpedior and its Subsidiaries has
experienced any material disruption in their Information Technology or in the
services and products provided to them by their vendors and suppliers as a
result of the occurrence of the year 2000. "YEAR 2000 READY" means that
Information Technology is designed to be used prior to, during and after the
calendar year 2000 A.D., and such Information Technology will accurately
receive, provide and process date/time data (including calculating, comparing,
sequencing and making leap year calculations) from, into and between the
twentieth and twenty-first centuries A.D., and will not malfunction, cease to
function or provide invalid or incorrect results as a result of any date/time
data (including to the extent that other Information Technology used in
combination with such Information Technology properly exchanges date/time data
with it).

     Section 2.15 Interested Party Transactions. Since its inception, or as
described in the SEC Reports, no event has occurred that would be required to be
reported by Xpedior pursuant to Item 404 of Regulation S-K promulgated by the
SEC. Except as expressly set forth in the Xpedior Disclosure Schedule, there are
no agreements, arrangements, understandings or commitments (including Debt,
guarantees, financial support or keep whole arrangements) between or involving
Xpedior or any one or more of its Subsidiaries, on the one hand, and Metamor or
any one or more of its Subsidiaries (other than Xpedior and its Subsidiaries),
on the other hand.

     Section 2.16 Environmental Matters. Except as disclosed on the Xpedior
Disclosure Schedule or in the SEC Reports, and excluding matters that would not
have an Xpedior Material Adverse Effect:

         (a) Xpedior and each of its Subsidiaries (i) are in compliance with all
Environmental Laws and are not subject to any asserted liability or, to
Xpedior's knowledge, any unasserted liability (including liability with respect
to current or former Subsidiaries or operations), under any Environmental Laws,
(ii) hold or have applied for all Environmental Permits required for their
properties or operations, and (iii) are in compliance with their respective
Environmental Permits;

         (b) none of Xpedior and its Subsidiaries has received any written
notice, demand, letter, claim or request for information alleging that Xpedior
or any of its Subsidiaries is or may be in violation of, or liable under, any
Environmental Law;

         (c) none of Xpedior and its Subsidiaries (i) has entered into or agreed
to any consent decree or order or is subject to any judgment, decree or judicial
order relating to compliance with Environmental Laws, Environmental Permits or
the investigation, sampling, monitoring, treatment, remediation, removal or
cleanup of Hazardous Materials and, to the knowledge of Xpedior and its
Subsidiaries, no investigation, litigation or other proceeding is pending or
threatened in writing with respect thereto, or (ii) has received written notice
asserting

                                      -13-
<PAGE>   17
that it is an indemnitor in connection with any threatened or asserted claim by
any third-party indemnitee for any liability under any Environmental Law or
relating to any Hazardous Materials; and

         (d) none of the real property owned or leased by Xpedior or any of its
Subsidiaries is listed on or, to the knowledge of Xpedior, proposed for listing
on the "National Priorities List" under CERCLA, as updated through the date
hereof, or any similar state or foreign list of sites requiring investigation or
cleanup.

For purposes of this Agreement:

     "CERCLA" means the Comprehensive Environmental Response, Compensation and
Liability Act of 1980, as amended.

     "ENVIRONMENTAL LAWS" means any applicable federal, state, local, foreign or
supranational statute, Law, ordinance, regulation, rule, code, treaty, writ or
order, and any enforceable judicial or administrative interpretation thereof,
including any judicial or administrative order, consent decree, judgment,
stipulation, injunction, permit, authorization, policy, opinion or agency
requirement, in each case having the force and effect of Law, relating to the
pollution, protection, investigation or restoration of the environment, health
and safety or natural resources, including those relating to the use, handling,
presence, transportation, treatment, storage, disposal, release, threatened
release or discharge of Hazardous Materials or noise, odor, wetlands, pollution,
contamination or any injury or threat of injury to Persons or property, or to
the siting, construction, operation, closure and post-closure care of waste
disposal, handling and transfer facilities.

     "ENVIRONMENTAL PERMITS" means any Permit, approval, identification number,
license or other authorization required under any Environmental Law.

     "HAZARDOUS MATERIALS" means (i) any petroleum, petroleum products,
by-products or breakdown products, radioactive materials, asbestos-containing
materials or polychlorinated biphenyls, or (ii) any chemical, material or other
substance defined or regulated as toxic or hazardous or as a pollutant or
contaminant or waste under any Environmental Law.

     Section 2.17 Restrictions on Business Activities. Except as set forth on
the Xpedior Disclosure Schedule, there is no Contract, judgment, injunction,
order or decree binding upon Xpedior or any of its Subsidiaries or any of their
properties which has had or could reasonably be expected to have the effect of
prohibiting or materially impairing (a) any material business practice of
Xpedior, any of its Subsidiaries or, to the knowledge of Xpedior, PSINet or any
of its Affiliates, or (b) the conduct of any material business by Xpedior, any
of its Subsidiaries or, to the knowledge of Xpedior, PSINet or any of its
Affiliates, as currently conducted or as currently proposed to be conducted by
Xpedior and its Subsidiaries.

     Section 2.18 Certain Business Practices. Neither Xpedior nor any of its
Subsidiaries, nor any director, officer, employee or agent of Xpedior or any of
its Subsidiaries, has in any material respect (a) used any funds for unlawful
contributions, gifts, entertainment or other unlawful payments relating to
political activity, (b) made any unlawful payment to any foreign or domestic
governmental official or employee or to any foreign or domestic political party
or

                                      -14-
<PAGE>   18
campaign or violated any provision of the Foreign Corrupt Practices Act of 1977,
as amended, (c) consummated any transaction, made any payment, entered into any
agreement or arrangement or taken any other action in violation of Section
1128B(b) of the Social Security Act, as amended, or (d) made any other unlawful
payment.

     Section 2.19 Insurance. Xpedior has adequate insurance covering all of the
customarily insurable liabilities, including product liability, director and
officer liability, and general and casualty liabilities, in each case with
financially secure insurers.

     Section 2.20 Brokers; Expenses. Except as set forth on the Xpedior
Disclosure Schedule, no agent, broker, finder, investment banker or other firm
or Person is or will be entitled to any broker's or finder's fee or other
similar commission or fee in connection with the Transactions based upon
arrangements made by or on behalf of Xpedior.

     Section 2.21 Private Offering.

         (a) Neither Xpedior nor any Person acting on its behalf has taken or
will take any action which might subject the offering, issuance or sale of the
Convertible Note (or the Series A Preferred Stock into which it is convertible
or the Common Stock into which the Series A Preferred Stock is convertible or
with which dividends upon the Series A Preferred Stock may be paid) to the
registration requirement of Section 5 of the Securities Act, or that would make
the Transactions ineligible for exemption under Rule 506 promulgated under the
Securities Act. Assuming the accuracy of the representations and warranties of
PSINet set forth in this Agreement, the offer, sale and issuance of the
Convertible Note to PSINet pursuant to this Agreement is exempt from the
registration requirement of Section 5 of the Securities Act.

         (b) Neither Xpedior nor any Person acting on its behalf has distributed
any offering materials in connection with the offering and sale of the
Convertible Note, or solicited any offer to buy or sell the Convertible Note by
means of any form of general solicitation or advertising.

         (c) Neither Xpedior nor any Person acting on its behalf has issued or
sold, or offered to issue or sell, any shares of the Convertible Note to any
Person other than PSINet.

     Section 2.22 Investment Company. Xpedior is not, and is not controlled by,
an "investment company" within the meaning of the Investment Company Act of
1940, as amended.

                                  ARTICLE III

                    REPRESENTATIONS AND WARRANTIES OF PSINET

     PSINet represents and warrants to Xpedior that, except as disclosed on the
PSINet Disclosure Schedule which has been delivered to Xpedior prior to the
execution of this Agreement (the "PSINET DISCLOSURE SCHEDULE"):

Section 3.1 Organization and Qualification. PSINet is a corporation duly
organized, validly existing and in good standing under the laws of the State of
New York.

                                      -15-
<PAGE>   19
     Section 3.2 Authority Relative to this Agreement. PSINet has all necessary
power and authority to execute and deliver this Agreement, to perform its
obligations hereunder and to consummate the Transactions. The execution and
delivery of this Agreement by PSINet, and the consummation by PSINet of the
Transactions, have been duly and validly authorized by all necessary corporate
action and no other corporate proceedings on the part of PSINet are necessary to
authorize the execution and delivery of this Agreement or to consummate the
Transactions. This Agreement has been duly and validly executed and delivered by
PSINet and, assuming the due authorization, execution and delivery hereof by
Xpedior, constitutes a legal, valid and binding obligation of PSINet,
enforceable against PSINet in accordance with its terms.

     Section 3.3 No Conflicts, Required Filings and Consents.

         (a) The execution and delivery of this Agreement by PSINet does not,
and the performance of this Agreement and consummation of the Transactions by
PSINet will not, (i) conflict with or violate the certificate of incorporation
or by-laws of PSINet, (ii) assuming the consents, approvals, authorizations and
waivers specified in Section 3.3(b) have been received and any condition
precedent to such consent, approval, authorization or waiver has been satisfied,
conflict with or violate any Law applicable to PSINet or by which any property
or asset of PSINet is bound or affected, or (iii) result in any breach of or
constitute a default (or an event which with notice or lapse of time or both
would become a default) under, or give to others any right of termination,
amendment, acceleration or cancellation of, or result in the creation of a lien
or other encumbrance on any property or asset of PSINet pursuant to, any
contract, agreement, note, bond, mortgage, indenture, credit agreement, lease,
license, permit, franchise or other instrument or obligation to which PSINet is
a party or by which PSINet or any property or asset of PSINet is bound or
affected, except in the case of clauses (ii) or (iii) for any such conflicts,
violations, breaches, defaults or other occurrences of the type referred to
above that would not prevent or materially delay the consummation of the
Transactions.

         (b) The execution and delivery of this Agreement by PSINet does not,
and the performance of this Agreement and consummation of the Transactions by
PSINet will not, require any consent, approval, authorization, waiver or permit
of, or filing with or notification to, any Governmental Entity, except as
required pursuant to the Exchange Act, Merger Control Laws, and regulations
promulgated thereunder, except where the failure to obtain such consents,
approvals, authorizations or permits, or to make such filings or notifications,
would not prevent or materially delay the consummation of the Transactions.

     Section 3.4 Brokers. Except as set forth on the PSINet Disclosure Schedule,
no agent, broker, finder, investment banker or other firm or Person is or will
be entitled to any broker's or finder's fee or other similar commission or fee
in connection with the Transactions based upon arrangements made by or on behalf
of PSINet.

     Section 3.5 Investment Intent. PSINet is acquiring the Convertible Note for
its own account for investment purposes only and not with a view to or for
distributing or reselling such Convertible Note, or any part thereof or interest
therein; provided, however, that this Section 3.5 shall not prejudice in any way
PSINet's right at all times to sell or otherwise convert or dispose of all or
any part of such Convertible Note (or all or any part of the Series A Preferred
Stock into which it may be converted or all or any part of the Common Stock
issuable as a dividend upon

                                      -16-
<PAGE>   20
the Series A Preferred Stock or into which the Series A Preferred Stock may be
converted) pursuant to an effective registration statement under the Securities
Act, or under an exemption from such registration, and, in each case, in
compliance with applicable Blue Sky Laws.

     Section 3.6 Status. PSINet is, and at the Closing Date, will be, an
"accredited investor" as defined in Rule 501(a) under the Securities Act.

                                   ARTICLE IV

                                    COVENANTS

     Section 4.1 Access to Information. As soon as practicable after the date
hereof, Xpedior shall use its reasonable best efforts to cooperate with and
assist PSINet and PSINet's independent public accountants in the compilation and
preparation of all financial statements and financial statement schedules of
Xpedior in accordance with GAAP, and to obtain such reports and consents of
Xpedior's independent public accountants, as may be necessary or deemed
advisable by PSINet to comply with its SEC reporting and disclosure
requirements, if any. Xpedior shall deliver to PSINet's independent public
accountants or Xpedior's independent public accountants all engagement letters
and management representation letters as may be reasonably requested by PSINet
or such accountants. Xpedior shall use its reasonable best efforts to cause its
independent public accountants to cooperate with and assist PSINet and its
independent public accountants in the preparation of any financial statements
contemplated by this Section 4.1.

     Section 4.2 Furnishing of Information. As long as PSINet owns the
Convertible Note or any shares of Series A Preferred Stock or Common Stock,
Xpedior covenants to timely file (or obtain extensions in respect thereof and
file within the applicable grace period) all reports required to be filed by
Xpedior after the date hereof pursuant to Section 13(a) or 15(d) of the Exchange
Act. If at any time prior to the date on which PSINet may resell all of the
shares of Common Stock acquired by it as a dividend upon, or upon conversion of,
the Series A Preferred Stock without volume restrictions pursuant to Rule 144(k)
promulgated under the Securities Act (as determined by counsel to Xpedior, which
may be counsel employed by Xpedior, pursuant to a written opinion letter to such
effect, if necessary, addressed and acceptable to Xpedior's transfer agent for
the benefit of and also addressed to PSINet) Xpedior is not required to file
reports pursuant to such sections, it will prepare and furnish to PSINet, and
make publicly available, information in accordance with Rule 144(c) promulgated
under the Securities Act. Xpedior further covenants that it will take such
further action as any holder of the Convertible Note or Series A Preferred
Shares may reasonably request, all to the extent required from time to time to
enable such Person to sell such shares of Common Stock without registration
under the Securities Act within the limitation of the exemptions provided by
Rule 144 promulgated under the Securities Act, including providing the legal
opinion referenced above in this Section 4.2 (if required by Xpedior's transfer
agent). Upon the request of any such Person, Xpedior shall deliver to such
Person a written certification of Xpedior executed by a duly authorized officer
on behalf of Xpedior as to whether it has complied with such requirements of
Rule 144(c).

     Section 4.3 Integration. Xpedior shall not, and shall use its reasonable
best efforts to ensure that none of its Affiliates, agents or representatives
shall, sell, offer for sale, solicit offers

                                      -17-
<PAGE>   21
to buy or otherwise negotiate in respect of any "security" (as defined in
Section 2 of the Securities Act) that would be integrated with the offer or sale
of the Convertible Note or the Series A Preferred Stock in a manner that would
require the registration under the Securities Act of the issue or sale of the
Convertible Note or the Series A Preferred Stock to PSINet.

     Section 4.4 Adoption of Shareholder Rights Plan. As long as PSINet or any
of its Affiliates owns the Convertible Note or any shares of Series A Preferred
Stock or Common Stock, Xpedior covenants not to implement a shareholder rights
plan, arrangement or any similar plan or agreement.

     Section 4.5 Information Statement. Xpedior shall promptly prepare and file
with the SEC an information statement relating to this Agreement, the
Transactions and the authorization and issuance of the Convertible Note
hereunder (the "INFORMATION STATEMENT"), incorporate in the Information
Statement the reasonable comments of PSINet and its counsel, and use all
reasonable efforts to cause the Information Statement to be mailed to its
shareholders as promptly as practicable after the date hereof pursuant to Rule
14c-2(b) under the Exchange Act. Xpedior shall mail the Information Statement
(and all other materials required to be mailed therewith) to its stockholders as
promptly as practicable after the passage of the ten-day period required by Rule
14c-5(a) under the Exchange Act and shall take all other actions required under
Regulation 14C under the Exchange Act in connection with this Agreement, the
Transactions and the issuance of the Series A Preferred Stock hereunder. PSINet
shall cooperate with Xpedior and provide Xpedior with such information, and
provide such other assistance, as Xpedior may reasonably request in order to
promptly prepare, file and mail the Information Statement.

     Section 4.6 Repayment of Metamor Note. Xpedior shall, on or before the
Closing Date, pay to Metamor the Metamor Payable.

     Section 4.7 Transfer Restrictions.

         (a) Securities may only be disposed of pursuant to an effective
registration statement under the Securities Act, to Xpedior, or pursuant to an
available exemption therefrom or in a transaction not subject to the
registration requirements thereof. In connection with any transfer of any
Securities other than pursuant to an effective registration statement or to
Xpedior, Xpedior may require that the transferor thereof provide to Xpedior an
opinion of counsel selected by the transferor, the form and substance of which
opinion shall be reasonably satisfactory to Xpedior, to the effect that such
transfer does not require registration under the Securities Act. Except as
otherwise expressly provided herein, neither the Convertible Note nor the Series
A Preferred Stock may be sold, hypothecated (other than pursuant to a bona fide
loan arrangement with a broker, dealer or financial institution), transferred or
otherwise conveyed by PSINet or any direct or indirect permitted transferee
thereof without the prior written consent of Xpedior, which consent shall not be
unreasonably withheld, delayed or conditioned. Notwithstanding the foregoing,
Xpedior hereby consents to and agrees to register on its book and records (i)
any transfer by PSINet to (A) any Affiliate of PSINet, or (B) any Affiliate of a
permitted transferee company, and (ii) any transfers among any such Affiliates
or permitted transferees. With respect to any such transfer, no documentation
shall be required other than (i) executed transfer documents, and (ii) an
executed instrument of such transferee pursuant to which such transferee makes
representations and warranties to Xpedior to the same effect as those as set
forth in

                                      -18-
<PAGE>   22
Sections 3.5 and 3.6 and agrees to be bound by the terms of this Agreement and
the Registration Rights Agreement. Any transferee of Securities pursuant to this
Section 4.7(a) shall have the rights and obligations of PSINet under this
Agreement and of a "Holder" under the Registration Rights Agreement.

         (b) PSINet agrees to the imprinting, so long as is required by this
Section 4.7(b) of the following legend on the Securities:

          NEITHER THESE SECURITIES [NOR THE SECURITIES INTO WHICH THESE
     SECURITIES ARE CONVERTIBLE] HAVE BEEN REGISTERED WITH THE SECURITIES AND
     EXCHANGE COMMISSION OR THE SECURITIES COMMISSION OF ANY STATE IN RELIANCE
     UPON AN EXEMPTION FROM REGISTRATION UNDER THE SECURITIES ACT OF 1933, AS
     AMENDED (THE "SECURITIES ACT"), AND, ACCORDINGLY, MAY NOT BE OFFERED OR
     SOLD EXCEPT PURSUANT TO AN EFFECTIVE REGISTRATION STATEMENT UNDER THE
     SECURITIES ACT OR PURSUANT TO AN AVAILABLE EXEMPTION FROM, OR IN A
     TRANSACTION NOT SUBJECT TO, THE REGISTRATION REQUIREMENTS OF THE SECURITIES
     ACT AND IN ACCORDANCE WITH APPLICABLE STATE SECURITIES LAWS.

Securities shall not contain the legend set forth above if the conversion of
Series A Preferred Stock, or other issuance of such Securities, occurs at any
time while a registration statement is effective with respect thereto under the
Securities Act or, in the event there is not such an effective registration
statement at such time, if in the opinion of counsel to Xpedior such legend is
not required under applicable requirements of the Securities Act (including
judicial interpretations and pronouncement issued by the staff of the SEC).
Xpedior agrees that it will provide PSINet, upon request, with a certificate or
certificates representing the Securities, free from such legend, at such time as
such legend is no longer required hereunder. Xpedior shall not make any notation
on its records or give any instructions to any transfer agent of Xpedior which
enlarge the restrictions on transfer set forth in this Section 4.7.

     Section 4.8 Acknowledgment of Dilution. Xpedior acknowledges that the
issuance of the Common Stock upon conversion of the Series A Preferred Stock may
result in dilution of the outstanding shares of Common Stock, which dilution may
be substantial under certain market conditions. Xpedior further acknowledges
that, subject to the terms of the Certificate of Designations and applicable
Law, after the Closing its obligations to issue Series A Preferred Stock in
accordance with the terms of the Convertible Note and to issue Common Stock in
accordance with the terms of the Series A Preferred Stock are unconditional and
absolute regardless of the effect of any such dilution.

     Section 4.9 Copies and Use of Disclosure Materials. Xpedior consents to the
use of the SEC Reports, any reports filed by Xpedior under the Exchange Act
after the date hereof and any information provided by Xpedior pursuant to
Section 4.2 of this Agreement, and any amendments and supplements thereto, by
PSINet in connection with resales of the Securities other than pursuant to an
effective registration statement. Xpedior makes no representation or warranty as
to the continued completeness or accuracy of any of the SEC Reports or any other
such reports and undertakes no obligations to update any of the SEC Reports or
any such reports

                                      -19-
<PAGE>   23
after the Closing Date, except as and to the extent required under the
Exchange Act and the Registration Rights Agreement.

     Section 4.10 Increase in Authorized Shares. At such time or times as
Xpedior would be, if a notice of conversion were to be delivered on such date,
precluded from converting the Convertible Note or the then outstanding Series A
Preferred Stock by reason of an insufficient number of authorized shares of
Series A Preferred Stock or Common Stock then being authorized for issuance, the
Board of Directors of Xpedior shall take the actions set forth in the
Convertible Note or the Certificate of Designations, as applicable.

     Section 4.11 Listing of Underlying Shares. Xpedior shall use its reasonable
best efforts to maintain the listing of its Common Stock on the Nasdaq National
Market (or any other national securities exchange or market on which the Common
Stock is then listed or quoted). In addition, if at any time the number of
shares of Common Stock then issuable upon conversion of all then issued shares
of Series A Preferred Stock, plus the number of shares of Common Stock reserved
for issuance upon payment of dividends upon the Series A Preferred Stock
(assuming all dividends are paid in shares of Common Stock), is greater than the
number of shares of Common Stock theretofore listed with the Nasdaq National
Market (and any such other national securities exchange or market), then Xpedior
shall promptly take such action to file an additional shares listing application
so that a number of shares equal to the number of shares of Common Stock as
would then be issuable upon conversion of all of the Series A Preferred Stock,
plus the number of shares of Common Stock reserved for issuance upon payment of
dividends upon the Series A Preferred Stock (assuming all dividends are paid in
shares of Common Stock), shall have been listed with the Nasdaq National Market
(and any such other national securities exchange or market).

     Section 4.12 Conversion Obligations of Xpedior. Xpedior shall honor
conversions of the Convertible Note and the Series A Preferred Stock and shall
deliver Series A Preferred Stock and Common Stock in accordance with the terms
and conditions and time periods set forth in the Convertible Note and the
Certificate of Designations, as applicable. Each of the parties hereto agrees
that the other party shall be entitled to an injunction or injunctions to
prevent breaches of the provisions of this Section 4.12 and to enforce
specifically this Section 4.12 and the terms and provisions of this Section 4.12
in any action instituted in any court of the United States or any state thereof
having jurisdiction over the parties to this Agreement and the matter, in
addition to any other remedy to which they may be entitled, at Law or in equity.

     Section 4.13 Rights and Warrants. If Xpedior, at any time while the
Convertible Note or any shares of Series A Preferred Stock are outstanding,
shall issue any rights and/or warrants to all of the holders of Common Stock as
a class entitling them to subscribe for or purchase shares of Common Stock, then
PSINet shall receive an amount of such rights and/or warrants equal to the
number of rights and/or warrants it would have received, at the time of issuance
of such rights and/or warrants, if it had then converted the Convertible Note
and all of its shares of Series A Preferred Stock and if all dividends due but
not yet paid on the Preferred Stock had been paid in shares of Common Stock.

                                      -20-
<PAGE>   24
                                   ARTICLE V

                               GENERAL PROVISIONS

     Section 5.1 Survival of Representations, Warranties and Agreements. The
representations, warranties, covenants and agreements in this Agreement shall
survive the Closing.

     Section 5.2 Notices. All notices or other communications under this
Agreement shall be in writing and shall be given (and shall be deemed to have
been duly given upon receipt) by delivery in person, by telecopy (with
confirmation of receipt), or by registered or certified mail, postage prepaid,
return receipt requested, addressed as follows:

     If to Xpedior:

         Xpedior Incorporated
         One North Franklin, Suite 1500
         Chicago, Illinois 60606
         Attention:   Executive Vice President and Chief Operating Officer
         Telecopy:    (312) 251-2460

     With a copy to:

         Xpedior Incorporated
         35 Corporate Drive, 4th Floor
         Burlington, Massachusetts 01803
         Attention:  Caesar J. Belbel, Esq., Senior Vice President,
                      General Counsel and Secretary
         Telecopy:  (781) 685-4726

     And to:

         Ropes & Gray
         One International Place
         Boston, Massachusetts 02110
         Attention:   Ann L. Milner, Esq.
         Telecopy:    (617) 951-7050

     If to PSINet:

         PSINet Inc.
         44983 Knoll Square
         Alexandria, Virginia 20147
         Attention:    Chairman and Chief Executive Officer
         Telecopy:    (703) 726-4250

                                      -21-
<PAGE>   25
     With a copy to:

         PSINet Inc.
         44983 Knoll Square
         Alexandria, Virginia 20147
         Attention:   Kathleen B. Horne, Esq., Senior Vice
                      President and General Counsel
         Telecopy:    (703) 726-5254

     And to:

         Nixon Peabody LLP
         437 Madison Avenue
         New York, New York 10022
         Attention:   Richard F. Langan, Jr., Esq.
         Telecopy:    (212) 940-9940

or to such other address as any party may have furnished to the other parties in
writing in accordance with this Section 5.2.

     Section 5.3 Specific Performance. The parties hereto agree that each party
shall be entitled to an injunction or restraining order to prevent breaches of
this Agreement, the Convertible Note, the Certificate of Designations or the
Registration Rights Agreement, and to enforce specifically the terms and
provisions hereof and thereof in any court of the United States or any state
having jurisdiction, this being in addition to any other right or remedy to
which such party may be entitled under this Agreement, the Convertible Note, the
Certificate of Designations or the Registration Rights Agreement, at Law or in
equity.

     Section 5.4 Entire Agreement. This Agreement, the Convertible Note, the
Certificate of Designations and the Registration Rights Agreement (including the
documents and instruments referred to herein and therein) constitute the entire
agreement and supersede all other prior agreements and understandings, both
written and oral, between the parties with respect to the subject matter hereof.

     Section 5.5 Assignments; Parties in Interest. Neither this Agreement nor
any of the rights, interests or obligations hereunder may be assigned by any of
the parties hereto (whether by operation of Law or otherwise) without the prior
written consent of the other party. Subject to the foregoing, this Agreement
shall be binding upon and inure solely to the benefit of (a) each party hereto,
and (b) any permitted transferee of the Convertible Note or shares of the Series
A Preferred Stock (or the Common Stock issuable in payment of dividends upon, or
upon conversion of, the Series A Preferred Stock), and nothing in this
Agreement, express or implied, is intended to or shall confer upon any other
Person any right, benefit or remedy of any nature whatsoever under or by reason
of this Agreement, including to confer third party beneficiary rights.

     Section 5.6 Governing Law. This Agreement shall be governed in all respects
by the Laws of the State of Delaware (without giving effect to the provisions
thereof relating to conflicts of Law). The non-exclusive venue for the
adjudication of any dispute or proceeding

                                      -22-
<PAGE>   26
arising out of this Agreement or the performance hereof shall be the courts
located in Newcastle County, Delaware, and the parties hereto each consents to
and hereby submits to the jurisdiction of any court located in Newcastle County,
Delaware or any Federal courts located in Delaware.

     Section 5.7 Headings; Disclosure. The descriptive headings herein are
inserted for convenience of reference only and are not intended to be part of or
to affect the meaning or interpretation of this Agreement. Any disclosure by
Xpedior or PSINet in any portion of its respective Disclosure Schedule shall be
deemed disclosure in each other portion of such Disclosure Schedule to which
such disclosure reasonably relates on its face.

     Section 5.8 Certain Definitions and Rules of Construction.

         (a) As used in this Agreement:

     "AFFILIATE", as applied to any Person, means any other Person directly or
indirectly controlling, controlled by, or under common control with, that
Person; for purposes of this definition, "control" (including, with correlative
meanings, the terms "controlling," "controlled by" and "under common control
with"), as applied to any Person, means the possession, directly or indirectly,
of the power to direct or cause the direction of the management and policies of
that Person, whether through the ownership of voting securities, by contract or
otherwise.

     "AGREEMENT" has the meaning set forth in the preamble to this Agreement.

     "ANNUAL FINANCIAL STATEMENTS" has the meaning set forth in Section 2.5(b).

     "BLUE SKY LAWS" has the meaning set forth in Section 2.4(b).

     "BENEFIT PLANS" has the meaning set forth in Section 2.8(a).

     "CERCLA" has the meaning set forth in Section 2.16.

     "CERTIFICATE OF DESIGNATIONS" has the meaning set forth in Section 1.2.

     "CLOSING" has the meaning set forth in Section 1.3.

     "CLOSING DATE" has the meaning set forth in Section 1.3.

     "CODE" has the meaning set forth in Section 2.8(a).

     "COMMON STOCK" has the meaning set forth in Section 2.2(a).

     "CONTRACTS" has the meaning set forth in Section 2.13.

     "CONVERTIBLE NOTE" has the meaning set forth in the preamble to this
Agreement.

     "DEBT" means, with respect to any Person, all indebtedness of such Person
for borrowed money or the deferred purchase price of property or services
(excluding trade payables and other accrued current liabilities arising in the
ordinary course of business), obligations of such Person evidenced by bonds,
notes, indentures or similar instruments, obligations of such Person under

                                      -23-
<PAGE>   27
interest rate agreements, currency hedging agreements, commodity price
protection agreements or similar hedging instruments, capital lease obligations
of such Person, redeemable capital stock of such Person and any other
obligations of such Person classified as indebtedness under GAAP.

     "ENVIRONMENTAL LAWS" has the meaning set forth in Section 2.16.

     "ENVIRONMENTAL PERMITS" has the meaning set forth in Section 2.16.

     "ERISA" has the meaning set forth in Section 2.8(a).

     "ERISA AFFILIATE" has the meaning set forth in Section 2.8(a).

     "EXCHANGE ACT" has the meaning set forth in Section 2.5(a).

     "FINANCIAL STATEMENTS" has the meaning set forth in Section 2.5(c).

     "GAAP" has the meaning set forth in Section 2.5(b).

     "GOVERNMENTAL ENTITY" has the meaning set forth in Section 2.4(b).

     "GOVERNMENTAL REGULATION" has the meaning set forth in Section 2.11.

     "HAZARDOUS MATERIALS" has the meaning set forth in Section 2.16.

     "INFORMATION STATEMENT" has the meaning set forth in Section 5.7.

     "INFORMATION TECHNOLOGY" has the meaning set forth in Section 2.14(c).

     "INTELLECTUAL PROPERTY RIGHTS" has the meaning set forth in Section
2.14(a).

     "IRS" has the meaning set forth in Section 2.8(c).

     "LAW" or "LAWS" means any domestic (federal, state or local), foreign or
supranational law, rule, regulation, order, judgment or decree.

     "LIENS" has the meaning set forth in Section 2.2(b).

     "MERGER CONTROL LAWS" means the Hart-Scott-Rodino Antitrust Improvements
Act of 1976, as amended, and the rules and regulations thereunder, and the Law
of any other Governmental Entity with respect to competition, mergers or other
business combinations.

     "METAMOR" has the meaning set forth in Section 1.4.

     "METAMOR PAYABLE" has the meaning set forth in Section 1.4.

     "NON-U.S. BENEFIT PLANS" has the meaning set forth in Section 2.8(l).

     "PERMITS" has the meaning set forth in Section 2.11.

                                      -24-
<PAGE>   28
     "PERSON" shall include individuals, corporations, partnerships, limited
liability companies, trusts, other entities and groups (which term shall include
a "group" as such term is defined in Section 13(d)(3) of the Exchange Act).

     "PREFERRED STOCK" has the meaning set forth in Section 2.2(a).

     "PROPERTY RIGHTS" has the meaning set forth in Section 2.12.

     "PSINET" has the meaning set forth in the preamble to this Agreement.

     "PSINET DISCLOSURE SCHEDULE" has the meaning set forth in Article III,
Introduction.

     "PURCHASE PRICE" has the meaning set forth in Section 1.1.

     "QUARTERLY FINANCIAL STATEMENTS" has the meaning set forth in Section
2.5(c).

     "REGISTRATION RIGHTS AGREEMENT" has the meaning set forth in Section 1.4.

     "SEC" has the meaning set forth in Section 2.5(a).

     "SEC REPORTS" has the meaning set forth in Section 2.5(a).

     "SECURITIES" means the Series A Preferred Stock and the Common Stock issued
or issuable as dividends upon, or upon conversion of, Series A Preferred Stock.

     "SECURITIES ACT" has the meaning set forth in Section 2.4(b).

     "SERIES A PREFERRED STOCK" has the meaning set forth in the preamble to
this Agreement.

     "STOCK OPTIONS" has the meaning set forth in Section 2.2(a).

     "SUBSIDIARY" or "SUBSIDIARIES" means, with respect to PSINet, Xpedior or
any other Person, any corporation, partnership, joint venture or other legal
entity of which PSINet, Xpedior or such other Person, as the case may be (either
alone or through or together with any other Subsidiary), owns, directly or
indirectly, stock or other equity interests the holders of which are generally
entitled to more than 50% of the vote for the election of the board of directors
or other governing body of such corporation or other legal entity.

     "TAX" means any federal, state, local, foreign or provincial income, gross
receipts, property, sales, service, use, license, lease, excise, franchise,
employment, payroll, withholding, employment, unemployment insurance, workers'
compensation, social security, alternative or added minimum, ad valorem, value
added, stamp, business license, occupation, premium, environmental, windfall
profit, customs, duties, estimated, transfer or excise tax, or any other tax,
custom, duty, premium, governmental fee or other assessment or charge of any
kind whatsoever, together with any interest, penalty or addition to tax imposed
by, any Governmental Entity.

     "TRANSACTIONS" means the transactions contemplated by this Agreement, the
Certificate of Designations and the Registration Rights Agreement.

                                      -25-
<PAGE>   29
     "XPEDIOR" has the meaning set forth in the preamble to this Agreement.

     "XPEDIOR BENEFIT PLANS" has the meaning set forth in Section 2.8(a).

     "XPEDIOR DISCLOSURE SCHEDULE" has the meaning set forth in Article II,
Introduction.

     "XPEDIOR MATERIAL ADVERSE EFFECT" means any circumstance, event or
occurrence, or any series of circumstances, events or occurrences, which
individually or in the aggregate with all other circumstances, events or
occurrences would be reasonably likely to have a material adverse effect on the
business, assets, operations, financial condition, revenues or results of
operations of Xpedior and its Subsidiaries taken as a whole, other than any
change, circumstances or effect relating to (i) a change after the date of this
Agreement in Law or GAAP, or in any interpretations thereof, that applies to
Xpedior or its Subsidiaries, (ii) the economy or securities markets in general,
or (iii) the industries in which Xpedior operates in general and not
specifically relating to Xpedior.

     "YEAR 2000 READY" has the meaning set forth in Section 2.14(c).

         (b) Other Rules of Construction.

            (i) References in this Agreement to any gender shall include
references to all genders. Unless the context otherwise requires, references in
the singular include references in the plural and vice versa. References to a
party to this Agreement or to other agreements described herein means those
Persons executing such agreements.

            (ii) The words "include", "including" and "includes" shall each be
deemed to be followed by the phrase "without limitation" or the phrase "but not
limited to" in all places where such words appear in this Agreement. The word
"or" shall be deemed to be inclusive.

            (iii) This Agreement is the joint drafting product of PSINet and
Xpedior, and each provision has been subject to negotiation and agreement and
shall not be construed for or against either party as drafter thereof.

            (iv) In each case in this Agreement where this Agreement or a
Contract is represented or warranted to be enforceable, such representation or
warranty will be deemed to include a limitation thereon to the extent that
enforceability may be subject to applicable bankruptcy, insolvency,
reorganization, fraudulent conveyance, moratorium or similar Laws affecting the
enforcement of creditors' rights generally and to general equitable principles,
whether applied in equity or at Law.

            (v) All references in this Agreement to financial terms shall be
deemed to refer to such terms as they are defined under GAAP, consistently
applied.

     Section 5.9 Counterparts. This Agreement may be executed in two or more
counterparts which together shall constitute a single agreement.

                                      -26-
<PAGE>   30
     Section 5.10 Severability. If any term or other provision of this Agreement
is invalid, illegal or incapable of being enforced by any rule of Law or public
policy, all other terms and provisions of this Agreement shall nevertheless
remain in full force and effect so long as the economics or legal substance of
the Transactions are not affected in any manner materially adverse to either
party. Upon determination that any term or other provision hereof is invalid,
illegal or incapable of being enforced, the parties hereto shall negotiate in
good faith to modify this Agreement so as to effect the original intent of the
parties as closely as possible to the fullest extent permitted by applicable Law
in an acceptable manner to the end that the Transactions are fulfilled to the
extent possible.

     Section 5.11 Fees and Expenses. Whether or not the Transactions are
consummated, all costs and expenses incurred in connection with this Agreement
and the Transactions shall be paid by the party incurring such expenses.

     Section 5.12 Amendment. This Agreement may not be amended except by an
instrument in writing signed on behalf of each of the parties hereto.

     Section 5.13 Waiver. At any time prior to the Closing, the parties hereto
may, to the extent permitted by applicable Law, (a) extend the time for the
performance of any of the obligations or other acts of the other party hereto,
(b) waive any inaccuracies in the representations and warranties by the other
party contained herein or in any documents delivered by the other party pursuant
hereto, and (c) waive compliance with any of the agreements of the other party
or with any conditions to its own obligations contained herein. Any agreement on
the part of a party hereto to any such extension or waiver shall be valid only
if set forth in an instrument in writing signed on behalf of such party.

                                      -27-
<PAGE>   31
     IN WITNESS WHEREOF, PSINet and Xpedior have caused this Agreement to be
signed by their respective officers thereunto duly authorized all as of the date
first written above.

                                   PSINET INC.

                                   By:    /s/ Harold S. Wills
                                   Name:  Harold S. Wills
                                   Title:  President and Chief Operating Officer

                                   XPEDIOR INCORPORATED

                                   By:    /s/ David N. Campbell
                                   Name:  David N. Campbell
                                   Title:  President and Chief Executive Officer

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