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                                                                   EXHIBIT 10.48
 
                          LICENSE PURCHASE AGREEMENT

     THIS LICENSE PURCHASE AGREEMENT (the "Agreement") is entered into as of the
__ day of July, 1997, to be effective as of the Effective Date, hereinafter
defined, between Concentric Network Corporation, a Florida corporation with
offices at 10590 N. Tantau Avenue, Cupertino, CA 95014 ("CNC") and Williams
Communications Group, a Delaware corporation with offices at One Williams Center
17th Floor, Tulsa, Oklahoma 74172 ("WCG").

In consideration of the mutual promises contained herein, CNC and WCG
(collectively the "PARTIES") agree as follows:

1.   Definitions.  For the purpose of this Agreement, the following terms and
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all terms defined elsewhere in this Agreement shall have the meanings so
defined.  A term defined in the singular shall include the plural and vice versa
when the context so indicates.

"Affiliate" shall mean any Person that directly or indirectly, through one or
more intermediaries, controls or is controlled by, or is under common control
with, the Person involved.

"Dispute Resolution Procedures" shall mean the dispute resolution procedures set
forth in Section 12 of this Agreement.

"Effective Date" shall be the Closing Date described in that certain Common
Stock and Warrant Purchase Agreement between the Parties entered into
concurrently with the execution of this Agreement.

"Change of Control" shall mean (i) any transaction in which CNC, or any direct
or indirect parent corporation of CNC, is, directly or indirectly, acquired by,
merged with or into or consolidated with, or reorganized into, another
corporation or other legal entity, and as a result of such acquisition, merger,
consolidation or reorganization less than a majority of the combined voting
power of the then-outstanding securities of CNC, or any direct or indirect
parent corporation of CNC, as the case may be, immediately after the transaction
are held in the aggregate by the persons holding such securities immediately
prior to the event; or (ii) any transaction in which CNC, or any direct or
indirect parent corporation of CNC, sells or otherwise transfers all or
substantially all of its assets to any other corporation or other person, if
less than a majority of the combined voting power of the then-outstanding
securities of such other person is held in the aggregate by the holders of
voting stock of CNC, or any direct or indirect parent corporation of CNC, as the
case may be; provided, however, that any such transactions will not include a
transaction where the other party to the transaction is a CNC Affiliate prior to
the transaction in question.

"Person" shall mean any natural person, firm, partnership, limited liability
company, association, corporation, company, trust, business trust, governmental
authority or other entity.

"WCG Competitor" shall mean any of the following companies and their successors
and assigns, and the Affiliates thereof: Qwest Communications Corporation, IXC
Communications Inc., MCI Communications Corporation, Sprint Corporation, AT&T
Corporation, WorldCom, Inc., GTE Corporation, and Ameritech Corporation.

"Intellectual Property" shall mean the copyrights, patents, trademarks or trade
secrets  underlying the Concentric Host, Concentric View, CityFind, Concentric
Internet Access Kit and Registration Service, Web University, FrontLine,
Adaptive Call Processing and Billing software programs, SMTP Server, POP3
Server, Web Server, News Server, IRC Server, Authentication Server, Registration
Servers, Internet Shell Server, Billing Server, Latency Tool, replacements,
updates and modifications of any of the foregoing, and other copyrights,
patents, 
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trademarks or trade secrets which Concentric owns or obtains the right to
assign, license or to otherwise transfer to a third party

2.   Agreement for Sale and Purchase.  In the event of a Change of Control to a
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WCG Competitor, WCG shall have the right to purchase at the then current market
value for a license of this type from CNC, or from the entity succeeding to
CNC's rights to the Intellectual Property as a result of the Change in Control,
a non-exclusive, perpetual, fully-paid-up license to use, reproduce, distribute,
and create derivative works of the Intellectual Property as it exists on the
date of the Change of Control at a price to be mutually determined.  CNC shall
notify WCG of any Change of Control within thirty (30) days thereof.  In the
event the parties cannot agree upon a price within ninety (90) days of the
Change of Control the issue of the price of the fully-paid-up license shall be
determined in accordance with the Dispute Resolution Procedures.

3.   Term.  This Agreement shall continue in effect for so long as WCG owns at
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least five percent (5%) of the outstanding common or preferred stock of CNC;
provided, however, that this Agreement shall not be caused to terminate by this
section if the reduction in WCG's ownership percentage below five percent (5%)
is caused by or occurs in connection with the subject Change of Control.

4.   LIMITATION ON LIABILITY.   IN NO EVENT SHALL EITHER PARTY BE LIABLE TO THE
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OTHER OR TO ANY OTHER ENTITY FOR ANY SPECIAL, CONSEQUENTIAL, INCIDENTAL, OR
INDIRECT DAMAGES, HOWEVER CAUSED ON ANY THEORY OF LIABILITY.

5.   Governing Law and Jurisdiction.  This Agreement shall be governed by and
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construed under the laws of the state of California, without reference to
conflict of law principles.
 
6.   Entire Agreement.  This Agreement sets forth the entire agreement and
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understanding of the parties relating to the subject matter herein and merges
all prior discussions between them.  No modification of or amendment to this
Agreement, nor any waiver of any rights under this Agreement, shall be effective
unless in writing signed by the party to be charged.
 
7.   Notices.  Any notice required or permitted by this Agreement shall be in
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writing and shall be deemed given (a) upon personal deliver, (b) on the third
day following mailing sent by registered or certified mail, return receipt
requested, postage prepaid, (c) upon confirmed delivery by means of a nationally
recognized overnight courier service or (d) upon confirmed transmission of
facsimile, addressed to the other party at the address shown at the beginning of
this Agreement or at such other address for which such party gives notice
hereunder.

8.   Non-Assignability and Binding Effect.  Neither party shall assign its
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rights or delegate its duties under this Agreement without the prior written
consent of the other party, which consent shall not be unreasonably withheld.
Notwithstanding the foregoing, WCG may, with written notice to CNC, assign this
Agreement to a direct or indirect subsidiary or other Affiliate of WCG.  Subject
to the foregoing, this Agreement shall be binding upon and inure to the benefit
of the parties hereto, their successors and assigns.

9.   Counterparts.  This Agreement may be executed in two or more counterparts,
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each of which shall be deemed an original.

10.  Headings.  The section headings contained in this Agreement are for
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reference purposes only and shall not affect in any way the meaning or
interpretation of this Agreement.

11.  Severability.  If any provision or part of a provision of this Agreement
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shall be invalid or unenforceable, 

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such invalidity or unenforceability shall not invalidate or render unenforceable
the entire Agreement or provision but rather the entire Agreement or provision
shall be construed as if not containing the particular invalid or unenforceable
provision or portion thereof, and the rights and obligations of CNC and WCG
shall be construed and enforced accordingly.

12.  Resolution of Disagreements Between Parties.  No party to this Agreement
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shall be entitled to take legal action with respect to any dispute relating
hereto until it has complied in good faith with the following alternative
dispute resolution procedures.  If a dispute, claim or controversy arises with
respect to or relates to any Section of this Agreement, then the following
dispute resolution procedures shall govern the parties' conduct:

     a.  The parties shall attempt promptly and in good faith to resolve any
dispute arising out of or relating to this Agreement through negotiations
between representatives who have authority to settle the controversy.  Either
party may give the other party written notice of any such dispute not resolved
in the normal course of business.  Negotiations extending ten (10) days after
the disputing party's notice shall be deemed at an impasse, unless otherwise
agreed by the parties.  If a negotiator intends to be accompanied at a meeting
by an attorney, the other negotiator(s) shall be given at least two (2) working
days notice of such intention and may also be accompanied by an attorney.  All
negotiations pursuant to this clause are confidential and shall be treated as
compromise and settlement negotiations for purposes of the Federal and State
Rules of Evidence.

     b.  If a dispute is at an impasse (i.e., it has not been resolved within
ten (10) days of the disputing party's notice), the dispute shall be settled by
arbitration administered by the American Arbitration Association in a mutually
convenient location, in accordance with the Commercial Arbitration Rules of the
American Arbitration Association in effect on the date that such notice is
given.  If the parties are unable to agree on a single arbitrator within ten
(10) days from the date of an impasse as set forth in Subsection (a), then the
CNC and WCG shall each select one arbitrator within ten (10) days and the two
(2) arbitrators shall select a third arbitrator within ten (10) days.  If a
party does not designate an arbitrator or if the two appointed arbitrators
cannot agree on the final arbitrator within the foregoing time periods, then the
American Arbitration Association shall select the arbitrator(s) upon request of
either party.  The arbitrator(s) shall not reach a decision which is different
than either of the positions taken by the parties.  In the event the
arbitrator(s) decide that neither party's position reflects the correct decision
according to the requirements for reaching a decision, then the arbitrator(s)
shall adopt the position of the party which the arbitrator(s) believe comes the
closest to representing what the arbitrator(s) believe is the correct decision
as the decision of the arbitrator(s). The decision of the arbitrator(s) shall be
final and binding upon the parties and shall include written findings of law and
fact, and judgment may be obtained thereon by either party in a court of
competent jurisdiction.  Each party shall bear the cost of preparing and
presenting its own case.  The cost of the arbitration, including the fees and
expenses of the arbitrator(s), shall be shared equally by the parties hereto
unless the award otherwise provides. The arbitrator(s) shall be instructed by
the parties to establish procedures such that a decision can be rendered by the
arbitrator(s) within sixty (60) days of the date that the last arbitrator is
selected.

 

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     c.  The obligation herein to arbitrate shall not be binding upon either
party with respect to requests for preliminary injunctions, temporary
restraining orders, specific performance or other procedures in a court of
competent jurisdiction to obtain interim relief when deemed necessary by such
court to preserve the status quo or prevent irreparable injury pending
resolution by arbitration of the actual dispute.

IN WITNESS WHEREOF the parties hereto have executed this Agreement as of the day
and year first above written, to be effective as of the Effective Date.

CONCENTRIC NETWORK                     WILLIAMS COMMUNICATIONS
CORPORATION                            GROUP, INC.
     ("CNC")                                      ("WCG")

   /s/ Henry R. Nothhaft                  /s/ S. Miller Williams
By:__________________________          By:_________________________________

Printed Name:________________          Printed Name:_______________________

Title:_______________________          Title:______________________________

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