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                                                                   EXHIBIT 10.62



                         REGISTRATION RIGHTS AGREEMENT

     This Registration Rights Agreement (this "Agreement") is made as of the
25th day of February, 1998 by and between PSINet Inc., a New York corporation
(the "Company"), and IXC Internet Services, Inc., a Delaware corporation
("IXC").

                                  WITNESSETH:

     WHEREAS, the Company and IXC have entered into an IRU and Stock Purchase
Agreement dated as of July 22, 1997, as amended, supplemented or modified (the
"IRU Agreement"), pursuant to which the Company will issue to IXC shares of
Common Stock.

     WHEREAS, it is a condition precedent to the consummation of the
transactions under the IRU Agreement that this Agreement be entered into.

     WHEREAS, the Company has previously granted registration rights to certain
other holders of the Company's securities pursuant to the Amended and Restated
Registration Rights Agreement, the 2/8/95 Registration Rights Agreement, the
6/16/95 Registration Rights Agreement, the 7/11/95 Registration Rights Agreement
and the 9/19/96 Registration Rights Agreement.

     WHEREAS, it is the intention of the parties to this Agreement that the
registration rights granted hereunder shall rank ratably with the registration
rights under the Amended and Restated Registration Rights Agreement, the 2/8/95
Registration Rights Agreement, the 6/16/95 Registration Rights Agreement, the
7/11/95 Registration Rights Agreement and the 9/19/96 Registration Rights
Agreement and with registration rights to be granted under other agreements as
more fully provided in Section 2.6 hereof.

     WHEREAS, certain defined terms are set forth in Article I hereof.

     NOW, THEREFORE, for good and valuable consideration, the receipt and
adequacy of which are hereby acknowledged, and in consideration of the mutual
covenants contained herein and for other good and available consideration, the
receipt and adequacy of which are hereby acknowledged, the parties hereto,
intending to be legally bound, agree as follows:

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                                   ARTICLE I

                                  DEFINITIONS

SECTION 1.1    CERTAIN DEFINITIONS

     As used in this Agreement, the following terms shall have the meanings
indicated below:

     "Amended and Restated Registration Rights Agreement" shall mean the Amended
and Restated Registration Rights Agreement dated as of January 17, 1995 among
the Company and the other parties thereto, as the same has been and hereafter
may be amended from time to time to add additional parties signatory thereto.

     "Closing" shall mean the closing of the transactions contemplated under the
IRU Agreement as more specifically defined therein.

     "Commission" shall mean the Securities and Exchange Commission or any other
federal agency at the time administering the Securities Act.

     "Common Stock" shall mean the Common Stock, $.01 par value per share, of
the Company.

     "Exchange Act" shall mean the Securities Exchange Act of 1934, as amended,
and the rules and regulations promulgated thereunder.

     "Existing Registration Rights" shall have the meaning set forth in Section
2.7 hereof.

     "Other Registration Rights" shall have the meaning set forth in Section 2.7
hereof.

     "Person" shall mean any individual, corporation, partnership, firm, joint
venture, association, limited liability company, trust, unincorporated
organization, or other entity.

     "Primary offering" shall have the meaning set forth in Section 2.1 hereof.

     "Registrable Securities" shall have the meaning set forth in Section 2.4
hereof.

     "Secondary offering" shall have the meaning set forth in Section 2.1
hereof.

     "Securities Act" shall mean the Securities Act of 1933, as amended, and the
rules and regulations promulgated thereunder.

     "2/8/95 Registration Rights Agreement" shall mean the Registration Rights
Agreement dated as of February 8, 1995 among the Company and the other parties
thereto, as the same 

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may be amended from time to time and, to the extent, if any, the same shall be
in effect on the date hereof and remain in effect from time to time hereafter.

     "6/16/95 Registration Rights Agreement" shall mean the Registration Rights
Agreement dated as of June 16, 1995 among the Company and the other parties
thereto, as the same may be amended from time to time and, to the extent, if
any, the same shall be in effect on the date hereof and remain in effect from
time to time hereafter.

     "7/11/95 Registration Rights Agreement" shall mean the Registration Rights
Agreement dated as of July 11, 1995 among the Company and the other parties
thereto, as the same may be amended from time to time and, to the extent, if
any, the same shall be in effect on the date hereof and remain in effect from
time to time hereafter.

     "9/19/96 Registration Rights Agreement" shall mean the Registration Rights
Agreement dated as of September 19, 1996 between the Company and The Chatterjee
Management Company, as the same may be amended from time to time and, to the
extent, if any, the same shall be in effect on the date hereof and remain in
effect from time to time hereafter.

                                  ARTICLE II

                              REGISTRATION RIGHTS

     SECTION 2.1    OPTIONAL REGISTRATIONS

     If at any time or times after the date hereof (so long as IXC shall own
Registrable Securities which are not eligible for sale by IXC under Rule 144(k)
of the Securities Act), the Company shall determine to register any shares of
Common Stock or securities convertible into or exchangeable or exercisable for
shares of the Common Stock under the Securities Act (whether in connection with
a public offering of securities by the Company (a "primary offering"), a public
offering of securities by shareholders (a "secondary offering"), or both, but
not in connection with a registration effected solely to implement an employee
benefit plan or a transaction to which Rule 145 or any other similar rule of the
Commission under the Securities Act is applicable), the Company will promptly
give written notice thereof to IXC.  In connection with any such registration,
if within 30 days after receipt of such notice IXC requests the inclusion of
some or all of the Registrable Securities in such registration, the Company,
subject to Section 2.7 hereof, will use its reasonable best efforts to effect
the registration under the Securities Act of all such Registrable Securities;
provided, that such registration is in connection with an underwritten public
offering; and provided, further, that, if the underwriter determines that the
registration of securities in excess of any amount to be registered by the
Company would adversely affect such offering then the Company may (subject to
the allocation priority set forth below) exclude from such registration and
underwriting some or all of the Registrable Securities which would otherwise be
underwritten pursuant to the notice described herein.  The Company shall advise
IXC promptly after such determination by the underwriter, and the number of
shares 

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of securities that are entitled to be included in the registration and
underwriting shall be allocated in the following manner: the securities to be
sold by the Company shall be included in such registration and underwriting,
and, subject to Section 2.7 hereof, the number of additional shares that may be
included in the registration and underwriting shall be allocated among IXC and
all holders of other securities having registration rights granted by the
Company requesting that such other securities be included in such registration
and underwriting in proportion, as nearly as practicable, to their respective
holdings of Registrable Securities and such other securities. All expenses of
the registration and offering shall be borne by the Company, except that IXC and
all holders of other securities having registration rights granted by the
Company shall bear underwriting and selling discounts and commissions
attributable to their Registrable Securities or such other securities, as the
case may be, being registered, transfer taxes on shares being sold by IXC or the
other holders, as the case may be, and all fees and expenses of counsel for IXC
and such holders, as the case may be. Without in any way limiting the types of
registrations to which this Section 2.1 shall apply, in the event that the
Company shall effect a "shelf registration" under Rule 415 of the Securities Act
or any other similar rule or regulation, the Company shall take all necessary
action, including, without limitation, the filing of post-effective amendments,
to permit IXC to include its shares in such registration in accordance with the
terms of this Section 2.1.

     SECTION 2.2    REQUIRED REGISTRATIONS

     At any time or times after the date hereof (so long as IXC shall own
Registrable Securities which are not eligible for sale by IXC under Rule 144(k)
of the Securities Act), IXC may notify the Company in writing that it (i)
intends to offer or cause to be offered for public sale all or any portion of
its Registrable Securities (such requests shall be in writing and shall state
the number of shares of Registrable Securities to be disposed of and the
intended method of disposition of such shares by IXC) and (ii) request that the
Company cause such Registrable Securities to be registered under the Securities
Act; provided, however, that IXC may make only three requests for registration
under this Section 2.2.  Upon receipt of such notification, subject to Section
2.7 hereof, the Company will notify all of the Persons who would be entitled to
notice of a proposed registration under Existing Registration Rights or Other
Registration Rights of its receipt of such notification.  Upon the written
request of any such Person delivered to the Company within 30 days after receipt
from the Company of such notification, the Company will use its reasonable best
efforts to cause such Registrable Securities as may be requested by IXC or such
securities as may be requested by any such Person to be registered under the
Securities Act within 125 days of the notification by IXC, in accordance with
the terms of this Section 2.2; provided, however, that unless such registration
becomes effective and remains in effect for 60 days, such registration shall not
be counted as one of the three requests for registration that may be made by IXC
under this Section 2.2.  IXC shall have the right to select the investment
banker(s) and manager(s) (which shall be of national standing and reputation) to
administer any underwritten public offering under this Section 2.2, subject to
the execution and delivery by such investment banker(s) to the Company of a
confidentiality agreement in form and substance satisfactory to the Company.  If
requested in writing by the Company, IXC and the other Persons participating in
a registration under this Section 2.2 shall negotiate in good faith with 

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any underwriters retained in connection with the underwriting of such
registration. In the case of the registration of Registrable Securities in
connection with an underwritten public offering under this Section 2.2, if the
underwriter determines that the registration of securities in excess of an
amount determined by such underwriter would adversely affect such offering, then
the Company may (subject to the allocation priority set forth below) exclude
from such registration and underwriting some or all of the Registrable
Securities and other securities which would otherwise be underwritten pursuant
to this Section 2.2. The Company shall advise IXC and the other Persons who
requested to participate in such registration promptly after such determination
by the underwriter, and the number of securities that are entitled to be
included in the registration and underwriting shall be allocated in the
following manner: subject to Section 2.7 hereof, the number of securities that
may be included in the registration and underwriting shall be allocated among
IXC and such other Persons requesting that Registrable Securities or other
securities be included in such registration and underwriting in proportion, as
nearly as practicable, to their respective holdings of Registrable Securities
and other securities; provided, however, that if the number of Registrable
Securities pursuant to such registration shall be reduced to a number which is
less than 80% of the number of Registrable Securities as to which IXC requested
registration pursuant to this Section 2.2, then such registration shall not be
counted as one of the three requests for registration that may be made by IXC
under this Section 2.2. All expenses of such registration and offering and the
reasonable fees and expenses of one independent counsel for IXC and the other
Persons who requested to participate in such registration shall be borne by the
Company; provided, however, that (i) the Company shall have no liability for
such expenses if such registration does not become effective due solely to the
action or failure to act of IXC and (ii) IXC and other Persons who requested to
participate in such registration shall bear underwriting and selling discounts
and commissions attributable to their Registrable Securities or other securities
being registered and transfer taxes on shares being sold by them. The Company
may postpone the filing of any registration statement required hereunder for a
reasonable period of time, not to exceed 90 days during any 12 month period of
time, if the Company has been advised by legal counsel that such filing would
require the disclosure of a material transaction or other matter and the Company
determines reasonably and in good faith that such disclosure would have a
material adverse effect on the Company. Notwithstanding anything in this Section
2.2 to the contrary, the Company shall not be required to effect a registration
under this Section 2.2 more than 135 days following the end of the Company's
fiscal year, if such registration shall require the preparation of audited
financial statements for any interim period not otherwise prepared by the
Company. If a demand registration is requested during such period, subject to
the second preceding sentence, the Company will commence such registration
promptly following the end of the next fiscal year. The Company will enter into
customary agreements (including underwriting agreements) reasonably acceptable
to the Company to facilitate the demand registrations provided for above.

                                       5
<PAGE>
 
     SECTION 2.3    FORM S-3 SHELF REGISTRATION

     IXC shall have the right to request and have effected up to one
registration every six months of Registrable Securities on Form S-3 or any
successor form or, if Form S-3 or any successor form is not available, any
appropriate form under the Act (the "Shelf Registration Statement") for an
offering to be made on a continuous basis covering all the Registrable
Securities (the "Shelf Registration") (such request shall be in writing and
shall state the number of shares of Registrable Securities to be disposed of and
the intended method of disposition of such shares by IXC) provided that the
Registrable Securities for which such registration is requested are not eligible
for sale by IXC under Rule 144(k) of the Securities Act. Subject to the
provisions of applicable law, the Company will use its reasonable best efforts
to (i) file the Shelf Registration Statement to effect the registration of all
shares of Registrable Securities within 30 days of such request and (ii) cause
the Shelf Registration Statement to become effective under the Act on or prior
to the date 45 days from the date of filing and (iii) keep the Shelf
Registration Statement continuously effective for 60 days from the date the
Registration Statement becomes effective under the Act. All expenses in
connection with a registration requested pursuant to this Section 2.3 shall be
borne by the Company; provided, however, that (i) the Company shall have no
liability for such expenses if such registration does not become effective due
solely to the action or failure to act of IXC and (ii) IXC shall bear
underwriting and selling discounts and commissions, if any, attributable to its
Registrable Securities being registered, transfer taxes on shares being sold by
it and all fees and expenses of its counsel. The Company may postpone the filing
of any registration statement required hereunder for a reasonable period of
time, not to exceed 90 days, if the Company has been advised by legal counsel
that such filing would require the disclosure of a material transaction or other
factor which would not otherwise be required to be disclosed at such time and
the Company determines reasonably and in good faith that such disclosure would
have a material adverse effect on the Company with respect to the registration
of the Registrable Securities. The shelf-registration statement may also include
securities held or to be held by other holders of the Company's securities.

     SECTION 2.4    REGISTRABLE SECURITIES

     For purposes of this Agreement, the term "Registrable Securities" shall
mean the Common Stock issued or issuable under the IRU Agreement and any Common
Stock issued or issuable with respect thereto by way of a stock dividend or
stock split or in connection with a combination of shares, recapitalization,
merger, consolidation or other reorganization.

     SECTION 2.5    FURTHER OBLIGATIONS OF THE COMPANY

     Whenever the Company is required under this Article II to register any
Registrable Securities, it agrees that it shall also do the following:

          (a)  Use its reasonable best efforts to diligently prepare and file
with the Commission a registration statement and such amendments and supplements
to said registration 

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statement and the prospectus used in connection therewith as may be necessary to
keep said registration statement effective (but, in the case of a registration
under this Agreement, for no more than 60 days after the initial effective date
of the registration statement) and to comply with the provisions of the
Securities Act with respect to the sale of securities covered by said
registration statement for the period necessary to complete the proposed public
offering; provided, however, the Company may suspend the effectiveness of any
registration statement filed hereunder for a reasonable period of time, not to
exceed 90 days, if the Company has been advised by legal counsel that
maintaining such effectiveness would require the disclosure of a material
transaction or other matter and the Company determines reasonably and in good
faith that such disclosure would have a material adverse effect on the Company;
provided, further, that in the event of any such suspension of effectiveness,
the 60 day period of effectiveness required above shall be deemed tolled for the
number of days the effectiveness of such registration statement was suspended
and, if any securities covered by such registration statement remain unsold, the
Company shall thereafter take all necessary actions, including, without
limitation, the filing of post-effective amendments, to cause such registration
statement to become effective for the remainder of such 60 day period;

          (b)  Furnish to IXC such copies of each preliminary and final
prospectus and such other documents as IXC may reasonably request to facilitate
the public offering of its Registrable Securities;

          (c)  Use its reasonable best efforts to register or qualify the
securities covered by said registration statement at the Company's expense under
the securities or "blue-sky" laws of such jurisdiction as IXC may reasonably
request, provided that the Company shall not be required to register or qualify
the securities in any jurisdictions which require it to qualify to do business
or subject itself to taxation or general service of process therein;

          (d)  Immediately notify IXC, at any time when a prospectus relating to
its Registrable Securities is required to be delivered under the Securities Act,
of any stop order issued or threatened by the Commission or of the happening of
any event as a result of which such prospectus contains an untrue statement of a
material fact or omits any material fact necessary to make the statements
therein not misleading, and, at the request of IXC, prepare a supplement or
amendment to such prospectus so that, as thereafter delivered to the purchasers
of such Registrable Securities, such prospectus will not contain any untrue
statement of a material fact or omit to state any material fact necessary to
make the statements therein not misleading;

          (e)  Cause all such Registrable Securities to be listed on NASDAQ or
included in each securities exchange or quotation system on which similar
securities issued by the Company are then listed;

          (f)  Otherwise use its reasonable best efforts to comply with all
applicable rules and regulations of the Commission and make generally available
to its security holders, in each case as soon as practicable, but not later than
30 days after the close of the period covered 

                                       7
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thereby, an earnings statement of the Company which will satisfy the provisions
of Section 11(a) of the Securities Act; and

          (g)  Choose the underwriters (except as otherwise provided in Section
2.2 hereof), auditors, Company legal counsel and financial printer to be engaged
by the Company in any such registration.

     SECTION 2.6    NO TRANSFER OF REGISTRATION RIGHTS

     The registration rights of IXC under this Agreement may not be transferred
or assigned except to IXC Communications, Inc. or a controlled affiliate of IXC
Communications, Inc.; provided that such transferee shall have entered into an
agreement substantially the same as that set forth in Section 15.8 of the IRU
Agreement.

     SECTION 2.7    PRIOR AND OTHER REGISTRATION RIGHTS AGREEMENTS

     Notwithstanding any provision hereof to the contrary, the provisions of
this Article II: (i) shall rank ratably with the registration rights granted
under the Amended and Restated Registration Rights Agreement (the "Amended
Registration Rights") and, to the extent the provisions of this Article II
conflict or are inconsistent with any such Amended Registration Rights, such
conflict or inconsistency shall be resolved in a manner which, to the greatest
extent reasonably feasible, affords IXC and the holders of such Amended
Registration Rights, the ratable benefits of this Article II and such Amended
Registration Rights; (ii) shall rank ratably with the registration rights
granted under the 2/8/95 Registration Rights Agreement (the "2/8/95 Registration
Rights") and, to the extent the provisions of this Article II conflict or are
inconsistent with any such 2/8/95 Registration Rights, such conflict or
inconsistency shall be resolved in a manner which, to the greatest extent
reasonably feasible, affords IXC and the holders of the 2/8/95 Registration
Rights, the ratable benefits of this Article II and such 2/8/95 Registration
Rights; (iii) shall rank ratably with the registration rights granted under the
6/16/95 Registration Rights Agreement (the "6/16/95 Registration Rights") and,
to the extent the provisions of this Article II conflict or are inconsistent
with any such 6/16/95 Registration Rights, such conflict or inconsistency shall
be resolved in a manner which, to the greatest extent reasonably feasible,
affords IXC and the holders of the 6/16/95 Registration Rights, the ratable
benefits of this Article II and such 6/16/95 Registration Rights; (iv) shall
rank ratably with the registration rights granted under the 7/11/95 Registration
Rights Agreement (the "7/11/95 Registration Rights") and, to the extent the
provisions of this Article II conflict or are inconsistent with any such 7/11/95
Registration Rights, such conflict or inconsistency shall be resolved in a
manner which, to the greatest extent reasonably feasible, affords IXC and the
holders of the 7/11/95 Registration Rights, the ratable benefits of this Article
II and such 7/11/95 Registration Rights; (v) shall rank ratably with the
registration rights granted under the 9/19/96 Registration Rights Agreement (the
"9/19/96 Registration Rights") and, to the extent the provisions of this Article
II conflict or are inconsistent with any such 9/19/96 Registration Rights, such
conflict or inconsistency shall be resolved in a manner which, to the greatest

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extent reasonably feasible, affords IXC and the holders of the 9/19/96
Registration Rights, the ratable benefits of this Article II and such 9/19/96
Registration Rights; and (vi) shall rank ratably with the registration rights to
be granted under any other agreement in connection with the original issuance of
any other capital stock of the Company (the "Other Registration Rights") and, to
the extent the provisions of this Article II shall conflict with any such Other
Registration Rights, such conflict shall be resolved in a manner which, to the
greatest extent reasonably feasible, affords IXC and the holders of such Other
Registration Rights, the ratable benefits of the provisions of this Article II
and such Other Registration Rights.


                                  ARTICLE III

                       INDEMNIFICATION AND CONTRIBUTION

     SECTION 3.1    INDEMNIFICATION

     Incident to any registration statement referred to in this Agreement, and
subject to applicable law, the Company will indemnify and hold harmless each
underwriter, IXC (including its directors, officers, employees and agents), and
each person who controls any of them within the meaning of Section 15 of the
Securities Act or Section 20 of the Exchange Act, from and against any and all
losses, claims, damages, expenses and liabilities, joint or several (including
any investigation, legal and other expenses incurred in connection with, and any
amount paid in settlement of, any action, suit or proceeding or any claim
asserted), to which they, or any of them, may become subject under the
Securities Act, the Exchange Act or other federal or state statutory law or
regulation, at common law or otherwise, insofar as such losses, claims, damages
or liabilities arise out of or are based on (i) any untrue statement or alleged
untrue statement of a material fact contained in such registration statement
(including any related preliminary or definitive prospectus, or any amendment or
supplement to such registration statement or prospectus), (ii) any omission or
alleged omission to state in such document a material fact required to be stated
in it or necessary to make the statements in it not misleading, or (iii) any
violation by the Company of the Securities Act, any state securities or "blue
sky" laws or any rule or regulation thereunder in connection with such
registration; provided, however, that the Company will not be liable to the
extent that such loss, claim, damage, expense or liability (x) arises from and
is based on an untrue statement or omission or alleged untrue statement or
omission made in reliance on and in conformity with information furnished in
writing to the Company by or on behalf of such underwriter, IXC or controlling
person expressly for use in such registration statement or (y) provided that the
Company has theretofore timely prepared all necessary prospectus supplements or
amendments and provided them to IXC or its representative, arises from the
failure of IXC or any underwriter to comply with such prospectus delivery
requirements as are applicable to it.  With respect to losses, claims, damages,
expenses and liabilities arising out of or based upon such untrue statement or
omission or alleged untrue statement or omission in the information furnished in
writing to the Company by or on behalf of IXC expressly for use in such
registration statement or such failure to comply with such prospectus delivery
requirements, IXC will indemnify and hold harmless each underwriter, the 

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Company (including its directors, officers, employees and agents), and each
person who controls any of them within the meaning of Section 15 of the
Securities Act or Section 20 of the Exchange Act, from and against any and all
losses, claims, damages, expenses and liabilities, joint or several, to which
they, or any of them, may become subject under the Securities Act, the Exchange
Act or other federal or state statutory law or regulation, at common law or
otherwise to the same extent provided in the immediately preceding sentence. In
no event, however, shall the liability of IXC for indemnification under this
Section 3.1 exceed the proceeds received by it from its sale of Registrable
Securities under such registration statement.

     SECTION 3.2    CONTRIBUTION

     If the indemnification provided for in Section 3.1 above for any reason is
held by a court of competent jurisdiction to be unavailable to an indemnified
party in respect of any losses, claims, damages, expenses or liabilities
referred to therein, then each indemnifying party under this Article III, in
lieu of indemnifying such indemnified party thereunder, shall contribute to the
amount paid or payable by such indemnified party as a result of such losses,
claims, damages, expenses or liabilities in such proportion as is appropriate to
reflect the relative benefits received by the Company, IXC and the underwriters
from the offering of the Registrable Securities as well as the relative fault of
the Company, IXC and the underwriters in connection with the statements or
omissions which resulted in such losses, claims, damages, expenses or
liabilities, as well as any other relevant equitable considerations.  The
relative benefits received by the Company, IXC and the underwriters shall be
deemed to be in the same respective proportions as the net proceeds from the
offering (before deducting expenses) received by the Company and IXC and the
underwriting discount received by the underwriters, in each case as set forth in
the table on the cover page of the applicable prospectus, bear to the aggregate
public offering price of the Registrable Securities.  The relative fault of the
Company, IXC and the underwriters shall be determined by reference to, among
other things, whether the untrue or alleged untrue statement of a material fact
or the omission or alleged omission to state a material fact relates to
information supplied by the Company, IXC or the underwriters and the parties'
relative intent, knowledge, access to information and opportunity to correct or
prevent such statement or omission.  The Company and IXC agree that it would not
be just and equitable if contribution pursuant to this Section 3.2 were
determined by pro rata or per capita allocation or by any other method of
allocation which does not take account of the equitable considerations referred
to in this paragraph.  In no event, however, shall IXC be required to contribute
any amount under this Section 3.2 in excess of the proceeds received by it from
its sale of Registrable Securities under such registration statement.  No person
found guilty of fraudulent misrepresentation (within the meaning of Section
11(f) of the Securities Act) shall be entitled to contribution from any person
who was not guilty of such fraudulent misrepresentation.

     SECTION 3.3    EXPENSES, ETC.

          (a)  The amount paid or payable by an indemnified party as a result of
the losses, claims, damages and liabilities referred to in this Article III
shall be deemed to include, subject to the limitations set forth above, any
legal or other expenses reasonably incurred by such 

                                       10
<PAGE>
 
indemnified party in connection with investigating or defending any such action
or claim. The indemnification and contribution provided for in this Article III
will remain in full force and effect regardless of any investigation made by or
on behalf of the indemnified parties or any officer, director, employee, agent
or controlling person of the indemnified parties.

          (b)  Notwithstanding the foregoing, to the extent that the provisions
on indemnification and contribution contained in an underwriting agreement
entered into in connection with any registration statement referred to in this
Agreement are in conflict with the foregoing provisions, the provisions in the
underwriting agreement shall control.


                                  ARTICLE IV

                                   RULE 144

     SECTION 4.1    RULE 144 REPORTING

     With a view to making available the benefits of certain rules and
regulations of the Commission which may permit the sale of the Registrable
Securities to the public without registration, the Company agrees to: (i) at all
times make and keep public information available as those terms are understood
and defined in Rule 144 under the Securities Act (and any successor rule to Rule
144); (ii) file with the Commission in a timely manner all reports and other
documents required of the Company under the Securities Act and the Exchange Act;
and (iii) furnish to IXC as promptly as possible upon its request a written
statement by the Company confirming its compliance with the reporting
requirements of Rule 144 and of the Securities Act and the Exchange Act, a copy
of the most recent annual or quarterly report of the Company, and any other
reports and documents so filed as IXC may reasonably request in availing itself
of any rule or regulation of the Commission allowing it to sell any such
securities without registration.

     SECTION 4.2    USE OF RULE 144

     IXC shall endeavor to sell its Registrable Securities whenever possible in
transactions pursuant to Rule 144 under the Securities Act (and any successor
rule to Rule 144) rather than pursuant to registrations effected under this
Agreement so long as such sales may be effected in compliance with the
requirements of Rule 144 (or any successor rule to Rule 144).

                                       11
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                                   ARTICLE V

                                    GENERAL

     SECTION 5.1    GRANTING OF RIGHTS AGREEMENTS

     The Company shall not grant any registration rights in respect of any
shares of capital stock of the Company or other securities of the Company if
such rights would be superior to the registration rights granted to IXC under
this Agreement; provided, however, that IXC hereby consents and agrees that the
Company may grant in other agreements to other holders of securities of the
Company registration rights which rank ratably with the registration rights
granted hereunder to IXC.

     SECTION 5.2    AMENDMENTS, WAIVERS AND CONSENTS

     For purposes of this Agreement and all agreements, documents and
instruments executed pursuant hereto, except as otherwise specifically set forth
herein or therein, no course of dealing between the Company and IXC and no delay
on the part of any party hereto in exercising any rights hereunder or thereunder
shall operate as a waiver of the rights hereof or thereof. No covenant or other
provision hereof or thereof may be waived or amended other than by a written
instrument signed by the party so waiving or amending such covenant or other
provision. Any waiver or amendment affected in accordance with this Section 5.2
shall be binding upon IXC and the Company at the time such waiver or amendment
is effected.

     SECTION 5.3    SURVIVAL OF COVENANTS; ASSIGNABILITY OF RIGHTS

     All covenants and agreements of the Company or IXC made herein shall
survive until fully discharged; provided, however, that notwithstanding any
provision of this Agreement to the contrary, in no event shall IXC be entitled
to any registration rights hereunder to the extent that it could sell pursuant
to Rule 144(k) under the Securities Act Registrable Securities which it desires
to register under the Securities Act pursuant to Sections 2.1, 2.2 or 2.3 hereof
or at any time after one year following the date at which the IRU Agreement is
no longer in effect. This Agreement may not be assigned by IXC except as set
forth in Section 2.6. All covenants and agreements of the Company herein shall
bind the Company's successors and assigns, whether so expressed or not, and,
except as otherwise provided in this Agreement, all such covenants and
agreements shall inure to the benefit of IXC's successors and assigns.

     SECTION 5.4    GOVERNING LAW

     This Agreement shall be governed by, and construed and enforced in
accordance with, the laws of the State of New York without reference to its
principles of conflicts of law.

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<PAGE>
 
     SECTION 5.5    HEADINGS

     The headings used in this Agreement have been inserted for reference
purposes only and shall not control or affect in any manner the meaning or
interpretation of any provision of this Agreement.

     SECTION 5.6    PRONOUNS

     All pronouns and any variation thereof, shall be deemed to refer to the
masculine, feminine or neuter, singular or plural, as the identity of the person
or persons may require.

     SECTION 5.7    NOTICES AND DEMANDS

     Any notice or demand which, by any provision of this Agreement or any
agreement, document or instrument executed pursuant hereto or thereto, except as
otherwise provided therein, is required or provided to be given shall be deemed
to have been sufficiently given or served and received for all purposes when
delivered or 5 days after being sent by certified or registered mail, postage
and charges prepaid, return receipt requested, or by express delivery providing
receipt of delivery, to the following addresses: if to the Company, at 510
Huntmar Park Drive, Herndon, Virginia 20170, or at such other address designated
by the Company to IXC in writing; if to IXC, at its mailing address maintained
on the books and records of the Company, or at such other address designated by
IXC to the Company in writing.

     SECTION 5.8    SEVERABILITY

     The invalidity or unenforceability of any provision of this Agreement shall
not affect the validity or enforceability of the remaining provisions of this
Agreement, and this Agreement shall be construed in all respects as if such
invalid or unenforceable provision were omitted.  All provisions of this
Agreement shall be enforced to the full extent permitted by law.

     SECTION 5.9    ENTIRE AGREEMENT

     This Agreement constitutes the entire agreement among the parties
pertaining to the subject matter hereof and supersedes and cancels all other
prior agreements, understandings, negotiations and discussions, whether written
or oral, relating to the subject matter hereof.

     SECTION 5.10   COUNTERPARTS

     This Agreement may be executed in one or more counterparts, each of which
shall be deemed to be an original, and all of which together shall be deemed one
and the same instrument.

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<PAGE>
 
     IN WITNESS WHEREOF, the parties have executed this Agreement as of the date
first above written.

                                          PSINet Inc.

                                          By:   /s/ David N. Kunkel
                                                --------------------------------
                                          Name:     David N. Kunkel
                                          Title: Senior Vice President, General 
                                                   Counsel and Secretary


Accepted and Agreed as of the
date first above written.

IXC Internet Services, Inc.

By:  /s/ Jeffrey C. Smith
   --------------------------------
Name:    Jeffrey C. Smith
Title:  Senior Vice President

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