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                                                                   EXHIBIT 10.96

                   COLLOCATION AND INTERCONNECTION AGREEMENT


     This Collocation and Interconnection Agreement (this "Agreement") is
entered into as of the 25th day of February, 1998, by and between IXC Internet
Services, Inc., a Delaware corporation ("IXC"), and PSINet Inc., a New York
corporation ("PSINet"). All capitalized terms used but not otherwise defined
herein shall have the meanings set forth in that certain IRU and Stock Purchase
Agreement entered into as of July 22, 1997 by and between IXC and PSINet (as
amended, supplemented or modified, the "Purchase Agreement"). In the event of
any conflict between the terms of this Agreement and those of the Purchase
Agreement, the terms of the Purchase Agreement shall control.


                            BACKGROUND AND PURPOSE

     This Agreement is made with reference to the following facts:

     A.  IXC and PSINet have entered into the Purchase Agreement pursuant to
which, among other things, PSINet has acquired from IXC the PSINet Fiber IRU,
the IRU Capacity and the option to order Bandwidth on the Available System and
IXC has acquired from PSINet shares of PSINet's common stock.

     B.  In connection with the Purchase Agreement, PSINet may wish to collocate
its telecommunications equipment ("Equipment") at IXC's premises or points-of-
presence ("POPs") and, or may wish to interconnect its Equipment to IXC's or
third party's equipment. This Agreement sets forth the terms and conditions on
which PSINet may collocate and, or interconnect its Equipment on IXC's premises.


                              TERMS OF AGREEMENT

     Accordingly, in consideration of the foregoing and of the mutual covenants
contained herein and for other good and valuable consideration, the receipt of
which is hereby acknowledged, the parties hereto agree as follows:

     1.  IXC PREMISES.  IXC's premises available for the collocation of PSINet's
Equipment or interconnection of PSINet's facilities are listed on Exhibit K to
the Purchase Agreement as it may be expanded from time to time (the "IXC
Premises" or "IXC POPs").

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     2.   COLLOCATION RIGHTS.

          2.1  COLLOCATION. IXC hereby grants to PSINet the right to locate,
install, maintain and operate Equipment at the IXC Premises for the duration of
the term of the Purchase Agreement. No use of the IXC Premises required or
permitted under this Agreement shall create or vest in PSINet any easements or
other ownership or property rights of any nature in IXC's real or personal
property or the IXC Premises.

          2.2  BASIC SERVICES.  In consideration of the maintenance fee that
PSINet is required to pay IXC under the section entitled System Maintenance and
                                                         ----------------------
POPs -Consideration set forth in the Purchase Agreement, IXC shall supply HVAC
-------------------
(Heating, Ventilation and Air Conditioning) for standard components, non-UPS AC
power and space for PSINet Equipment at the IXC POPs as follows:

     SITES                         # OF SPACES**       POWER  PER SPACE
     -----                         -------------       ----------------

     As listed on Exhibit K              *                     *

** A space adequate to contain a cabinet (measuring 2 feet (width) x 3 feet
(depth) x 70 inches (height)).  PSINet shall supply its own cabinets.  If PSINet
has more, or desires more, than six Spaces in the IXC POPs, PSINet shall be
required to pay for those Spaces at IXC's standard rates.

          2.3  INTERFACE.  Interface points for PSINet's IRU Capacity provided
by IXC under the Purchase Agreement shall be at fiber patch panels ("Connect
Panels") located in the IXC Premises.  The Connect Panel located in the IXC
Premises shall be the demarcation to establish PSINet's operational and
maintenance responsibilities.  Subject to the space limitations set forth in
this Agreement, PSINet shall provide, install and maintain at its expense the
electronic equipment at the IXC Premises it desires.  PSINet will pay IXC time
and materials agreed upon on a case by case basis for equipment installation,
tech-assists and build-outs for power, cabling and HVAC.

          2.4  ADDITIONAL SERVICES.  In the event PSINet desires installation
services (including, but not limited to cross connect facilities needed to
access local exchange carriers' or competitive access providers' entrance
facilities), DC power, or additional space, AC power or HVAC (collectively
referred to as the "Services") at any of the IXC Premises, it shall make a
written request for such Services to IXC.  Within fifteen (15) business days
after receiving such written request, IXC shall provide PSINet with the
availability of the Services and IXC's standard rates for the Services.  In the
event upgrades or expansions to the IXC Premises or its facilities are necessary
to accommodate PSINet's request, IXC may include the entire cost of such
upgrades or expansions in the cost to PSINet.  In the event IXC provides the
Services to PSINet by replacing its existing equipment at PSINet's expense, IXC
shall give the old, replaced equipment to PSINet.  In

* Confidential material has been omitted and filed separately with the
  Securities and Exchange Commission.

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the event PSINet chooses to receive additional Services at the IXC Premises,
PSINet shall pay any and all (initial and continuing) costs reasonably
determined by IXC to be necessary to provide Services to PSINet. If IXC makes
available and PSINet utilizes more than 20 amps of AC power per Space during any
particular month during the term of this Agreement, PSINet shall pay IXC its
standard rate for each additional amp. IXC shall provide PSINet with an invoice
setting forth the costs for additional Services within sixty (60) days of the
later of: (a) IXC receiving its invoices for such Services from subcontractors
and vendors or (b) delivering the Services to PSINet. PSINet shall pay IXC the
amounts due within thirty (30) days of receipt of an invoice from IXC.

          2.5  BACK-UP POWER.  In the event that PSINet desires back-up power at
the IXC POPs, PSINet shall submit its back-up power requirements to IXC.  IXC
shall within thirty days of receipt of PSINet's request provide PSINet with a
quote as to IXC's costs for providing such back-up power; provided however, that
IXC shall only be obligated to provide such quote and the back-up power if IXC,
in its sole discretion, determines that providing such back-up power is feasible
considering available space, environmental factors, required consents from third
parties and other relevant factors.  In the event IXC does provide back-up power
to PSINet: (a) IXC shall provide PSINet with invoices setting forth the costs
for such back-up power within sixty (60) days of the later of: (i) IXC receiving
its invoices from subcontractors and vendors for installing and providing such
back-up power or (ii) delivering the back-up power to PSINet; and (b) IXC will
have no liability whatsoever to PSINet with regard to any delay, failure or
defect in such back-up power and Section 18 shall apply to such power.  IXC's
initial and ongoing costs for providing such back-up power to PSINet may be
included in IXC's invoices to PSINet.  PSINet shall pay IXC the amounts due
within thirty (30) days of receipt of an invoice from IXC.

          2.6  DELIVERY AND INSTALLATION.  PSINet shall, at its own expense,
deliver, install and maintain its collocated Equipment in a safe condition and
meeting or exceeding the standards set forth in Section 7.2.  At no additional
charge, IXC shall provide to PSINet Spaces that are reasonably proximate to each
other in light of the type of Equipment that PSINet is installing; provided,
however, that if PSINet or its Equipment requires a specific geometric
arrangement, and IXC determines that in order to accommodate PSINet or its
Equipment, rearrangement of the existing facilities at the IXC Premises is
required, PSINet agrees to reimburse IXC for any such make-ready costs.  IXC
will advise PSINet in writing of any estimated make-ready charges (including
investigation, design and engineering fees) for such rearrangement work and
PSINet shall make payment to IXC within thirty (30) days from its receipt of
IXC's invoice therefor.

     3.   INTERCONNECTION WITH PSINET POPS.

          3.1  CONSTRUCTION AND INSTALLATION.  In the event PSINet desires to
connect any of its POPs to any IXC POP, PSINet may construct, install, operate
and maintain a connection facility (the "POP-to-POP Interconnect Facility")
                                         --------------------------------  
between the PSINet premises and the IXC Premises so long as PSINet meets or
exceeds the standards set forth in Section 7.2.  PSINet shall provide at its
expense all necessary rights-of-way, permits, equipment and IXC-approved
materials to construct and install each POP-to-POP Interconnect Facility,
including, but not limited to, cables and conduit and any labor charges
associated therewith.  If necessary, and where applicable, IXC shall use

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commercially reasonable efforts to provide PSINet, at PSINet's expense, access
to existing building entrance facilities, if available, to access and exit IXC
POPs. The demarcation point for PSINet shall be in the IXC POPs at the Connect
Panel or the DSX panel, as appropriate.

          3.2  OWNERSHIP.  PSINet shall retain ownership of any portion of the
POP-to-POP Interconnect Facility that is located on the IXC Premises during the
term of this Agreement; provided, however, that title to any part of the POP-to-
POP Interconnect Facility within the IXC Premises shall be transferred to IXC
upon expiration or termination of this Agreement.

          3.3  MAINTENANCE AND CHANGES.  PSINet shall be responsible for
maintenance and repair of the POP-to-POP Interconnect Facility on PSINet's side
of the point of demarcation.  Any improvement, modification, addition to,
relocation, or removal of, the POP-to-POP Interconnect Facility by PSINet at the
IXC Premises is subject to prior review and written approval by IXC Transmission
Engineering Department and the cost of such improvement, modification, addition
to, relocation, or removal of, the POP-to-POP Interconnect Facility will be the
sole responsibility of PSINet.  IXC's approval will not be unreasonably withheld
and in the event IXC fails to respond to PSINet's written request within thirty
(30) days of receiving PSINet's request for such changes, IXC's shall be deemed
to have approved PSINet's request.

     4.   INTERCONNECTION TO THIRD PARTIES.  Interconnect facilities to
interconnect PSINet's equipment to other parties within IXC's POPs shall be
installed and maintained subject to available space at the IXC POPs and under
the following terms and conditions:

     (a)  IXC shall provide PSINet at each POP with free interconnections
          (crossconnects) between PSI and third parties in units of DS-3's, as
          specified by PSINet, not to exceed, in the aggregate, the bandwidth
          capacity of the circuits PSINet has ordered at the POP.  Such free
          interconnections are not transferable to other POPs and any other
          connections shall be referred to as "Additional Interconnects" subject
          to the charges in Exhibit E to the Purchase Agreement.  Should
          subsequent interconnections become necessary after initial
          installation, up to the aggregate bandwidth capacity of the circuits
          PSINet has ordered at the POP, realignment of the interconnections
          shall be subject to the preceding and to the reconfiguration charges
          as indicated in Exhibit E.  All such interconnections shall be subject
          to the provisions of Section 15.5 of the Purchase Agreement.

     (b)  PSINet shall reimburse IXC for the capital cost to establish a point
          of demarcation for Additional Interconnects that PSINet requests IXC
          to provide.  This demarcation shall be in the IXC equipment room and
          shall be either the IXC standard DSX termination or fiber distribution
          frame as is applicable for the interconnects required.


     (c)  IXC shall charge PSINet a one time charge and a monthly recurring
          charge for each Additional Interconnect in the IXC POP.  These charges
          shall be an amount equal to the then standard ancillary pricing for
          such service set forth on Exhibit E to the 

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          Purchase Agreement. Nothing in this Agreement shall prevent or in any
          way limit IXC's ability to charge third parties for interconnection.

     (d)  In the event IXC chooses to cross-connect with an Additional
          Interconnect party for which PSINet has paid a charge to IXC under
          Section 4(b), IXC shall at IXC's option: (i) refund to PSINet such
          charge or (ii) shall pay PSINet a monthly cross-connect fee negotiated
          by the parties at such time.

     (e)  IXC's maintenance responsibility shall be limited to the demarcation
          point and the associated cross connect at that point.

     (f)  PSINet shall not use any interconnect facility to allow third parties
          collocated in any POP to interconnect with each other at that POP.

     5.   NOTICE TO INTERCONNECT OR COLLOCATE.  No later than forty-five (45)
days prior to PSINet's planned installation of its Equipment or POP-to-POP
Interconnect Facilities at any IXC Premises, PSINet shall provide to IXC notice
of its desire to interconnect/locate in a particular IXC Premise, a copy of
PSINet's construction design drawings and installation schedule for IXC's review
and approval (collectively referred to hereon as the "Interconnect/Collocation
Notice").  The Interconnect/Collocation Notice shall (at a minimum) include: (a)
PSINet's installation date(s); (b) any excess cable storage requirements; (c)
identification of all POP-to- POP Interconnect Facilities and Equipment to be
installed; (d) a diagram of the desired location of the POP-to-POP Interconnect
Facilities and Equipment; (e) the space, power, environmental and other
requirements for the POP-to-POP Interconnect Facilities and Equipment; (f) the
estimated commencement and termination dates for the
interconnection/collocation; (g) all other information reasonably required by
IXC.  PSINet's Equipment shall be placed and maintained in accordance with IXC's
requirements and specifications.  Within two weeks of receiving the
Interconnection/Collocation Notice, IXC shall respond to PSINet's
Interconnection/Collocation Notice with its acceptance or objections.

     6.   REQUIRED AUTHORIZATIONS.  PSINet shall obtain, at its sole cost and
expense, from any appropriate public and/or private authority, any required
permission, authorization, permit, license or easement (collectively, the
"Authorizations") to bring fiber to the IXC Premises and, or needed to
construct, install, operate and maintain the POP-to-POP Interconnect Facility
and to use the property over which the POP-to-POP Interconnect Facility will be
operated and maintained.  PSINet represents and warrants that such
Authorizations shall be in effect for the entire Term of this Agreement.  IXC
shall cooperate with PSINet in its efforts to obtain such authorizations.

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     7.   USE OF EQUIPMENT AND POP-TO-POP INTERCONNECT FACILITIES.

          7.1  NO INTERFERENCE.  PSINet shall not use its fibers, Equipment or
POP-to- POP Interconnect Facilities, and IXC shall not use its fiber, equipment
or interconnect facilities in any way which interferes with the other party's
use of its fibers or equipment or in any manner which violates any of the terms
or conditions of this Agreement or the Purchase Agreement.  PSINet shall not
install any electrical or other equipment that overloads any electrical
paneling, circuitry or wiring.

          7.2  STANDARDS.  PSINet shall ensure that its equipment and any POP-
to-POP Interconnect Facilities (as defined) are installed to meet or exceed any
reasonable requirements of IXC, any requirements of IXC's building management,
and any applicable local, state and federal codes and public health and safety
laws and regulations (including fire regulations and the National Electric
Code).  In the event IXC's building management or any local, state or federal
body determines the POP-to-POP Interconnect Facility is not in compliance with
the applicable laws and regulations, PSINet shall immediately make any changes
necessary such that the POP-to-POP Interconnect Facility no longer conflicts
with such law or regulations.  PSINet further agrees to comply with the
requirements of IXC's or IXC's building management's insurance underwriter(s).

          7.3  INTERVENTION.  If any part of PSINet's fiber, POP-to-POP
Interconnect Facilities or Equipment is not placed and maintained in accordance
with the terms and conditions of this Agreement and PSINet fails to correct the
violation within thirty days from receipt of written notice thereof from IXC,
then IXC may, at its option, without further notice to PSINet, correct the
deficiency at PSINet's expense without liability for damages to the fiber, POP-
to-POP Interconnect Facilities or Equipment or for any interruption of PSINet's
services.  As soon as practicable thereafter, IXC shall advise PSINet in writing
of the work performed or the action taken.  PSINet shall reimburse IXC for all
expenses incurred by IXC associated with any work or action performed by IXC
pursuant hereto.  PSINet shall remit payment to IXC within thirty days from its
receipt of IXC's invoice therefor.

          7.4  THREAT TO PERSONS OR PROPERTY.  In the event, and in IXC's sole
determination, if PSINet's fiber, POP-to-POP Interconnect Facilities or
Equipment poses an immediate threat to the safety of IXC employees or the
public, interferes with the performance of IXC's service obligations, or poses
and immediate threat to the physical integrity of IXC's facilities, IXC may
perform such work and/or take such action that it deems necessary without notice
to PSINet and without subjecting itself to any liability for damage to the
fiber, POP-to- POP Interconnect Facilities or the Equipment or for any
interruption of PSINet's services.  As soon as practicable thereafter, IXC shall
advise PSINet in writing of the work performed or the action taken.  PSINet
shall reimburse IXC for all expenses incurred by IXC associated with any work or
action performed by IXC pursuant hereto.  PSINet shall remit payment to IXC
within thirty days from its receipt of IXC's invoice therefor.

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     8.   Access to IXC Premises.

          8.1  NOTICE.  Except as specifically set forth in the Purchase
Agreement, the terms in this Section 8 shall govern PSINet's access to the IXC
Premises.  In the event PSINet's Equipment or POP-to-POP Interconnect Facilities
are located in the IXC Premises Customer Interface Facility ("CIF"), PSINet may
perform routine preventative maintenance or emergency maintenance and repairs on
its Equipment or POP-to-POP Interconnect Facilities during normal business hours
(7 am - 6 pm local time) without advance notice to IXC.  In the event PSINet
desires to: (a) perform routine preventative maintenance or emergency
maintenance and repairs during non-business hours; (b) perform any procedures
other than routine preventative maintenance (such as installation, removal or
relocation of its Equipment or POP-to-POP Interconnect Facilities); (c) perform
any function outside of the CIF or (d) access (on PSINet's side of the
demarcation point) the fibers leading from the IXC electronics which provide the
IRU Capacity, PSINet may do so if: (x) it provides reasonable advance notice to
IXC; and (y) a IXC employee or representative is present on the IXC Premises at
the time.  Notice provided as follows shall be deemed "reasonable advance
notice" for the purposes of this section: (i) twenty-four (24) hours for routine
preventative maintenance during non-business hours or outside the CIF; (ii) two
(2) hours for repairs of network malfunction causing loss of service or degraded
conditions (during non-business hours or outside the CIF), provided that such
period shall be reasonably tolled to permit IXC to dispatch personnel to an un-
manned IXC Premise upon receipt of a request for access thereto; (iii) two (2)
weeks notice for removing POP-to-POP Interconnect Facilities and, or Equipment
(regardless of location or time) and (iv) forty-five (45) days (as set forth in
Section 5) for installing Equipment or POP-to-POP Interconnect Facilities
(regardless or location or time).  The presence of a IXC employee or
representative shall not relieve PSINet of its responsibility to conduct all of
its work operations in the IXC Premises in a safe and workmanlike manner.  Under
no circumstances shall PSINet have access to any fibers on the IXC side of the
demarcation point.

          8.2  SECURITY.  PSINet shall abide by IXC's reasonable security
requirements.  When deemed appropriate by IXC, PSINet employees or
representatives shall be issued passes or visitor identification cards which
must be presented upon request before entry to the IXC Premises and surrendered
upon demand or upon termination of this Agreement.  Such passes or other
identification shall be issued only to persons meeting any reasonable security
criteria applicable at the IXC Premise for such purpose.  Notwithstanding any
other provision of this Agreement, IXC shall, without threat of liability, have
the right to immediately terminate the right of access of any PSINet personnel
or representative should it determine in its sole discretion for any lawful
reason that such termination is in its best interest.  IXC shall promptly notify
PSINet of any such termination, and PSINet shall have a reasonable opportunity
to demonstrate that the terminated rights of access should be reinstated.  Any
termination of access shall remain in effect pending such demonstration and
IXC's final determination as to the advisability of such reinstatement.

     9.   RELOCATION.  PSINet shall, at its own expense, relocate its fiber,
POP-to-POP Interconnect Facilities and Equipment upon IXC's written request and
in the reasonable (under the circumstances) time frame required by IXC.  Such
relocations could be within the IXC POP or in 

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the event the entire IXC POP is relocated. In any such event, IXC shall provide
the following services at no cost to PSINet: (i) site make-ready; (ii) the 
intra-site cabling functionally equivalent to that which existed in the prior
IXC POP; (iii) relocation of IXC's IRU circuits and equipment used by PSINet;
and (iv) re-establishing competitive access provider and local exchange carrier
interconnects common to both IXC and PSINet.

     10.  NO RESTRICTIONS.  Except as specifically set forth in the Purchase
Agreement, nothing contained in this Agreement shall be construed as a
limitation, restriction or prohibition against IXC with respect to any agreement
or arrangement which IXC has heretofore entered into, or may in the future enter
into, with others not parties to this Agreement regarding the IXC Premises.
IXC's right to maintain and operate its facilities in such a manner as will best
enable it to fulfill its own service requirements is in no manner limited by
this Agreement.

     11.  INSPECTIONS.  IXC reserves the right to make periodic inspections of
any part of the fiber, POP-to-POP Interconnect Facilities and Equipment located
within or physically attached to the IXC Premises; provided that PSINet shall
have the right to have one or more of its employees or representatives present
during the time of any such inspection.  IXC shall give PSINet advance notice of
such inspections, except in those instances where, in the sole judgment of IXC,
safety considerations justify the need for such an inspection without the delay
of providing notice.  The making of periodic inspections or the failure to do so
shall not operate to impose upon IXC any liability of any kind whatsoever nor
relieve PSINet of any responsibility, obligation, or liability assumed under
this Agreement.

     12.  EMERGENCIES.  In the event of an emergency:

          (a)  IXC's work shall take precedence over any and all operations of
          PSINet in the IXC Premises and IXC may rearrange PSINet's Equipment or
          POP-to-POP Interconnect Facilities.

          (b)  IXC shall use reasonable efforts to provide PSINet with advance
          notice of any such work.

          (c)  IXC shall use reasonable care given the circumstances when
          handling PSINet Equipment.

     13.  LIENS AND ENCUMBRANCES.  PSINet shall not have the power, authority or
right to create and shall not permit any lien or encumbrance, including, without
limitation, tax liens, mechanics' liens, or other liens or encumbrances with
respect to work performed, in connection with the installation, repair,
maintenance or operation of its Equipment, POP-to-POP Interconnect Facilities or
other property installed within the IXC Premises.

     14.  TERM.  This Agreement shall become effective as of its execution by
both parties and shall continue in effect until such time as it is terminated on
the earlier of (a) the expiration or 

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termination of the Purchase Agreement or (b) such time as it is terminated as
provided herein or by operation of law.

     15.  SUBORDINATION.  PSINet agrees that its rights under this Agreement
shall be totally subordinate to any mortgages, loans, deeds of trust or any
other borrowing upon the real or personal property which may be incurred by IXC.
PSINet shall sign any such reasonable documents as are necessary to satisfy any
lender, private or institutional, to reflect said subordination.

     16.  RELEASE; INDEMNIFICATION.  Each party (each party in such capacity
being referred to as the "Releasing Party") releases, assumes and agrees to
                          ---------------                                  
indemnify, defend, protect and save the other party harmless from and against
any claim, damage, loss, liability, cost and expense (including reasonable
attorneys' fees) in connection with any loss or damage to any physical property
or facilities of the Releasing Party or any injury to or death of any person
arising out of or resulting in any way from the negligence or misconduct of the
Releasing Party or its employees, servants, contractors and/or agents.

     17.  LIMITATION OF LIABILITY.

          17.1 EQUIPMENT AND FACILITIES.  IXC, its employees or subcontractors
shall not be liable for any damages to PSINet's fiber, POP-to-POP Interconnect
Facilities and Equipment collocated on the IXC Premises, except to the extent
that such damages are caused by the gross negligence or intentional acts of IXC,
its agents or employees; provided that the maximum liability of IXC for any
damage to PSINet's fiber, POP-to-POP Interconnect Facilities and Equipment shall
not exceed the replacement value of the fiber, POP-to-POP Interconnect
Facilities and Equipment, or in the event that the fiber, POP-to-POP
Interconnect Facilities and the Equipment is repairable, the costs to restore
the fiber, POP-to-POP Interconnect Facilities and the Equipment to its original
condition.  IXC shall not be liable for any damages of whatever nature,
including, but not limited to actual or consequential damages, arising from any
interruption or failure in the supply of utilities to the IXC Premises.

          17.2 NO CONSEQUENTIAL DAMAGES.  Except as specifically provided for in
the Purchase Agreement, in no event shall IXC or PSINet be liable for any
special, incidental, direct, indirect, punitive, reliance or consequential
damages, whether foreseeable or not, arising under this Agreement or from any
breach or partial breach of the provisions of this Agreement or occasioned by
any defect in the Bandwidth or other service provided hereunder, delay in
availability of the Bandwidth or any service provided hereunder, failure of the
Bandwidth or other service provided hereunder, interruptions or outages of the
Available System or any other cause whatsoever or arising out of any act or
omission by IXC or PSINet, as applicable, its employees, servants and/or agents,
including but not limited to, damage or loss of property or equipment, loss of
profits or revenue, cost of capital, cost of replacement services, or claims of
customers for service interruptions or transmission problems.

     18.  DISCLAIMER OF WARRANTY.   IXC MAKES NO WARRANTY TO PSINET OR ANY OTHER
PERSON OR ENTITY, WHETHER EXPRESS, IMPLIED, OR STATUTORY, AS 

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TO THE DESCRIPTION, QUALITY, MERCHANTABILITY, COMPLETENESS OR FITNESS FOR ANY
PARTICULAR PURPOSE OF ANY PREMISES, FACILITIES, SERVICES, EQUIPMENT, POWER,
CABLE OR FIBERS PROVIDED HEREUNDER OR DESCRIBED HEREIN, OR AS TO ANY OTHER
MATTER, ALL OF WHICH WARRANTIES ARE HEREBY EXCLUDED AND DISCLAIMED. NO OTHER
WARRANTIES ARE EXPRESSED OR IMPLIED, INCLUDING WARRANTIES OF MERCHANTABILITY OR
FITNESS FOR A PARTICULAR PURPOSE.

     19.  DEFAULT/TERMINATION.

          19.1 DEFAULT.  A party may deliver to the other party a written
"Notice of Default" for: (i) failing to make any payment owed hereunder, when no
bona fide dispute exists (a "Monetary Default"); or (ii) the breaching by either
                             ----------------                                   
party or its agents, assigns or affiliates of any Material Provision; or (iii)
the filing or initiating of proceedings by or against a party seeking
liquidation, reorganization or other such relief under any federal or state
bankruptcy or insolvency law (a "Bankruptcy Proceeding").  Such Notice of
Default must prominently contain the following sentences in capital letters:
"THIS IS A FORMAL NOTICE OF A BREACH OF CONTRACT  FAILURE TO CURE SUCH BREACH
WILL HAVE SIGNIFICANT LEGAL CONSEQUENCES." A party that has received a Notice of
Default shall have five (5) business days to cure a Monetary Default, thirty
(30) days to cure the alleged breach of any Material Provision (and, if the
defaulting party shall have commenced actions in good faith to cure such
defaults which are not susceptible of being cured during such 30-day period,
such period shall be extended (but not in excess of 90 additional days) while
such party continues such actions to cure), and shall be given ninety (90) days
to remove, have dismissed or stay any involuntary Bankruptcy Proceeding (each
such period, a "Cure Period").  If such party fails to cure the breach within
the Cure Period, as long as such default shall be continuing, the non-defaulting
party shall have the right to either (a) suspend its performance or payment
obligations under this Agreement, (b) seek an order of specific performance,
and/or (c) seek the award of compensatory damages.

          19.2 REMOVAL UPON TERMINATION.  Upon termination of this Agreement for
any reason other than a material default by IXC, PSINet shall remove, at its
sole expense, its fiber, POP-to-POP Interconnect Facilities and Equipment within
ten (10) days following such termination.  In the event PSINet fails to remove
its fiber, POP-to-POP Interconnect Facilities and Equipment within such ten (10)
day period, the fiber, POP-to-POP Interconnect Facilities and Equipment shall be
deemed abandoned and IXC, at its sole discretion and without liability, may
remove the fiber, POP-to-POP Interconnect Facilities and Equipment and be
reimbursed by PSINet for all costs associated with such removal.  PSINet shall
make payment to IXC for any such costs within thirty days of its receipt of an
invoice containing such costs.  In the event this Agreement terminates due to a
material default by IXC, either PSINet or IXC may remove the PSINet Equipment or
POP-to-POP Interconnect Facilities at its own expense upon fifteen (15) working
days written notice to the other party.

                                       8
<PAGE>
 
     20.  INSURANCE.  PSINet shall, at its expense, obtain and keep in full
force and effect at all times for the duration of this Agreement, with a carrier
or carriers satisfactory to IXC, insurance policies of the following kinds and
in the following amounts:

          (a)  Worker's Compensation Insurance in accordance with all applicable
laws;

          (b)  Employer's liability insurance with limits for employer's
liability of $500,000 per accident;

          (c)  Comprehensive bodily injury and property damage liability
insurance, including automobile insurance and contractual liability insurance,
in at least the following amounts:

<TABLE>
<CAPTION>
     <S>                                               <C>
     Bodily injury to any one person                   $1,000,000
     Bodily injury aggregate per occurrence            $1,000,000
     Property damage in any one accident               $  500,000
     Property damage aggregate per occurrence          $1,000,000
</TABLE>

Upon request of IXC, PSINet shall furnish IXC certificates of such insurance
and/or copies of the applicable policies, and each policy shall provide that no
change or cancellation shall become effective except upon twenty (20) days prior
written notice to IXC of such change or cancellation.  In the event of any
change or cancellation not acceptable to IXC, IXC may demand that PSINet obtain
replacement coverage.  If PSINet fails to obtain replacement coverage within
twenty (20) days after such demand by IXC, IXC may obtain replacement coverage
and invoice all premiums therefore to PSINet.  PSINet shall make payment to IXC
for any amount of such invoices within thirty days of its receipt thereof.

     21.  ASSIGNMENT.  Except as provided below, this Agreement may not be
assigned in whole or in part without the prior written consent of IXC. PSINet
may assign this Agreement in whole, but not in part and only in connection with
a permitted assignment of all of PSINet's rights and obligations under the
Purchase Agreement to an entity that is both a permitted assignee under the
section entitled Binding Effect; Assignment in the Purchase Agreement and a
                 --------------------------   
permitted transferee under the section entitled Restrictions on Resale in the
                                                ----------------------
Purchase Agreement; provided, however, that any such assignment or transfer
shall be subject to IXC's rights under this Agreement and an assignee or
transferee shall continue to perform PSINet's obligations to IXC under the terms
and conditions of this Agreement. This Agreement shall be binding upon and shall
inure to the benefit of the parties hereto and their respective successors and
assigns.

     22.  NOTICES.  All notices, claims, demands and other communications under
this Agreement shall be in writing and shall be deemed given when delivered
personally, the next business day after delivered to a nationally recognized
overnight courier for next business day delivery, when transmitted by facsimile
or five (5) days after sent by registered or certified mail, return receipt
requested, to the parties (and to the Persons receiving copies thereof) at the
following addresses or facsimile numbers (or to such other address or facsimile
number as a party may have specified by notice given to the other party pursuant

                                       9
<PAGE>
 
to this provision):

          If to IXC to:

               IXC Internet Services, Inc.
               1122 Capital of Texas Highway South
               Austin, Texas 78746
               Attention: Chief Financial Officer
               Facsimile: (512) 328-0239

          With copies to:

               IXC Communications, Inc.
               1122 Capital of Texas Highway South
               Austin, Texas 78746
               Attention: General Counsel
               Facsimile: (512) 328-7902

               Riordan & McKinzie
               695 Town Center Drive, Suite 1500
               Costa Mesa, California 92626
               Attention: Michael P. Whalen
               Facsimile: (714) 549-3244

          If to PSINet to:

               PSINet Inc.
               510 Huntmar Park Drive
               Herndon, Virginia 20170
               Attention: Chairman
               Facsimile: (703) 904-1608

          With copies to:

               PSINet Inc.
               510 Huntmar Park Drive
               Herndon, Virginia 20170
               Attention: General Counsel
               Facsimile: (703) 904-9527

                                      10
<PAGE>
 
               Nixon, Hargrave, Devans & Doyle LLP
               437 Madison Avenue
               New York, New York 10022
               Attention: Richard F. Langan, Jr.
               Facsimile: (212) 940-3111


     23.  GENERAL PROVISIONS.

          23.1  LAWS AND LICENSES.  This Agreement is subject to all applicable
federal, state and local laws, regulations, rulings and orders of governmental
agencies, including, but not limited to, the Communications Act of 1934 as
amended by the Telecommunications Act of 1996, and the rules and regulations of
the FCC. IXC and PSINet agree that, except as otherwise provided herein, the
statute of limitations set forth in the Communications Act of 1934, 47 U.S.C.
section 415, as amended, shall govern all actions arising out of this Agreement,
including arbitrations.

          23.2  CONFIDENTIALITY.  This Agreement shall be governed by the terms
of the Confidentiality Agreement entered into between the parties and dated as
of May 14, 1997.

          23.3  AMENDMENTS, WAIVERS AND CONSENTS.  For purposes of this
Agreement and the Transaction Documents, except as otherwise specifically set
forth herein or therein, no course of dealing between PSINet and IXC and no
delay on the part of either party hereto in exercising any rights hereunder or
thereunder shall operate as a waiver of the rights hereof and 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.

          23.4  SECTION HEADINGS.  The table of contents and section headings in
this Agreement have been inserted for reference purposes only and shall not be
deemed to limit or otherwise affect the construction of any provision thereof or
hereof.

          23.5  GOVERNING LAW.  This Agreement shall be deemed to be a contract
made under, and shall be construed in accordance with, the laws of the State of
Delaware without reference to its principles of conflicts of law.

          23.6  DISPUTE RESOLUTION.  Any controversies, claims or disputes
arising out of or relating to this Agreement shall be resolved in the manner set
forth in the section entitled Dispute Resolution in the Purchase Agreement.

          23.7  SEVERABILITY.  In the event that any one or more of the clauses,
covenants or provisions contained in this Agreement should be held to be
unenforceable under any Federal, State or City law, statute, code,
administrative or regulatory rule, such invalidity or unenforceability shall not
affect the remainder of this Agreement, which shall remain in full force and
effect.

                                      11
<PAGE>
 
          23.8  INTERPRETATION.  This Agreement shall be interpreted in a manner
so as to be consistent with the Purchase Agreement and under the same rules of
construction and interpretation set forth in the Purchase Agreement.

          23.9  COUNTERPARTS.  This Agreement may be executed simultaneously in
any number of counterparts, each of which when so executed and delivered shall
be taken to be an original, but such counterparts shall together constitute but
one and the same document.

          23.10 FACSIMILE DELIVERY.  This Agreement may be delivered by
facsimile transmission of an executed counterpart signature page hereof, and
after attachment of such transmitted signature page to a copy of this Agreement,
such copy shall have the same effect and evidentiary value as copies delivered
with original signatures. Any party delivering this Agreement by facsimile
transmission shall deliver to the other party, as soon as practicable after such
delivery, an original executed counterpart signature page of this Agreement.

     IN WITNESS WHEREOF, the parties hereto have duly executed this Agreement as
of the day and year first above written.


                                        IXC Internet Services, Inc.

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


                                        PSINet Inc.

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

                                      12