EXHIBIT 10.23
UUNET
An MCI WorldCom Company

CONFIDENTIAL MATERIALS HAVE BEEN OMITTED FROM THIS EXHIBIT PURSUANT TO A REQUEST
FOR  CONFIDENTIAL  TREATMENT AND HAVE BEEN FILED  SEPARATELY WITH THE SECURITIES
AND EXCHANGE COMMISSION. ASTERISKS DENOTE OMISSIONS.

UUNET
AN MCI WorldCom Company

                       MASTER INTERNET SERVICES AGREEMENT

                  This Master Internet Services Agreement  ("Agreement") is made
by and between UUNET  Technologies,  Inc.,  with its  principal  offices at 3060
Williams  Drive,   Fairfax,   VA  22031  ("UUNET")  and  Savvis   Communications
("Customer") with its principal offices at 7777 N. Boonhomme,  #1000, St. Louis,
Missouri  63105 for the  purpose  of  setting  forth  the  terms and  conditions
relating  to the  purchase  of UUNET's  Internet  products  and  services by the
Eligible Participants, as defined in Section 1 below.

                  1. DEFINITIONS.  "Affiliate" means with respect to a party, an
entity  controlled by,  controlling,  or under common control with,  such party.
"Effective Date" means the effective date of this Agreement,  which shall be the
last  date  of the  signature  of a duly  authorized  representative  of a party
affixed below.

                  2. SERVICES.  The services currently  available hereunder from
UUNET and its Affiliates  ("Services") are set forth in the attached Schedule 1.
UUNET may amend  Schedule 1 from time to time to remove  Services if they should
be  discontinued or to add new services (which shall be included within the term
Services  upon such  addition)  by  providing  a revised  copy of  Schedule 1 to
Customer. Such amendments shall be prospective only, shall be effected only upon
at least six  months'  prior  written  notice and shall not affect any  existing
Service  being  provided by UUNET or its  Affiliates  to Customer at the time of
amendment.

                  3.  PRICING.  The  prices  for  Services  applicable  to  this
Agreement  (exclusive of any telco and equipment  changes,  which are Customer's
responsibility),  are  detailed in Schedule  1, and shall be  applicable  to new
services  only in the United  States and to the  Services  in effect on the date
hereof as of the date of this  Agreement  referenced  as UUNET  account  numbers
U03914,  U04418,  U04419,  U05810,  U05811,  U05814,  U05817 and U05049.  UUNETs
obligation to provision  any service  under this  Agreement and to make Services
available  at the  prices  set forth on  Schedule  1 shall be  conditioned  upon
receipt from Customer on or before the date of this  Agreement of a certified or
cashier's check in the amount of at least $475,000.00, in which case, the prices
set forth on  Schedule  1 shall be  applicable  as of April 2, 1999 Any  Service
shall  only be  available  if the  Customer  agrees  to the  standard  terms and
conditions  applicable  to  such  Service  (as  modified  by the  terms  of this
Agreement)  and commits to purchase  that  Service for at least a one-year  term
from the date of Service installation.

                  4.  FORECASTS.  Two  weeks  prior to the end of each  calendar
quarter Customer shall, based on the best available information, provide UUNET a
forecast of orders likely to be generated  pursuant to this Agreement during the
subsequent  quarter on a per Service basis.  Within two weeks of receipt of each
forecast,


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UUNET shall provide to Customer  non-binding  estimated  installation  times for
such forecasted orders.

                  5. SERVICE ORDERS AND  COORDINATION.  Customer will coordinate
all orders for Services through UUNET's  designated  Account  Manager.  Customer
will enter into an Agreement  for Service  using  UUNET's  then-current  service
agreement.  Each service  agreement  shall set forth the terms and conditions of
the Service,  provided, that (a) Monthly Fees for the Service shall be set forth
in this Agreement, and (b) any service level agreements and related credit terms
set forth in such service  agreement  shall not apply to any Services under this
Service Agreement.

                  6. TERM.  The initial  term of this  Agreement  shall be three
years from the Effective Date. Thereafter, this Agreement shall be automatically
renewed for  additional  one (1) year terms,  provided  that  neither  party has
delivered  to the  other  a  written  notice  of  intent  not to  renew  for the
forthcoming term not less than 60 days in advance of the end of the then-current
term.  Customer may  terminate  any Service if the Service fails to meet for any
three-month  consecutive  period  the  Latency  Guarantee  set forth in  UUNET's
Service  Level  Agreement,  as in  effect  from  time to time and  available  at
www.uunet/customers/sla/terms.html  after Customer provides UUNET at least sixty
60 days' written notice of such intention to terminate and the Latency Guarantee
is not met for at least thirty 30 days during such 60-day period.

                  7. LIMITATION OF LIABILITY.  NOTWITHSTANDING  ANYTHING ELSE TO
THE CONTRARY STATED OR IMPLIED HEREIN OR IN ANY SERVICE AGREEMENT, NEITHER PARTY
SHALL  HAVE ANY  LIABILITY  TO THE  OTHER  PARTY  WHATSOEVER  FOR ANY  INDIRECT,
INCIDENTAL,  CONSEQUENTIAL,  PUNITIVE,  OR SPECIAL  DAMAGES,  INCLUDING  WITHOUT
LIMITATION, LOSS OF PROFIT, LOSS OF REVENUE, OR LOSS OF BUSINESS SUFFERED BY THE
OTHER OR BY ANY  ELIGIBLE  PARTICIPANT,  ASSIGNEE,  OR OTHER  TRANSFEREE  OF THE
OTHER. EVEN IF INFORMED IN ADVANCE OF THE POSSIBILITY OF SUCH DAMAGES.

                  8.  ACCEPTABLE  USE.  UUNET's  Services  may  only be used for
lawful purposes. Use of any Service must comply with the then-current version of
the UUNET Acceptable Use Policy  ("Policy") for the country in which the service
is provided,  available at the following  URL:  www.uunet/usepolicy,  and in the
event no Policy is available for that country the U.S. policy shall apply. UUNET
reserves  the right to change  the  Policy  from  time to time,  effective  upon
posting of the revised  Policy at the URL.  UUNET  reserves the right to suspend
the Service or terminate this Agreement effective upon notice for a violation of
the Policy.

                  9. INVOICING AND PAYMENT.  UUNET will invoice Customer for the
Service  ordered by  Customer  in  accordance  with the terms of the  applicable
service


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<PAGE>

agreement,  provided,  that in addition to the early cancellation fees set forth
therein,  Customer shall pay an additional  cancellation fee equal to telco fees
for a sixty (60) day period if UUNET has ordered the  applicable  telco circuit.
Customer will make payment for such Service in accordance  with the terms of the
applicable service agreement.

                  10. PUBLICITY.  Neither party shall publicize the existence of
this Agreement  without the written consent of the other.  Neither party may use
the name,  logo,  trademarks,  service marks, or other  proprietary  identifying
symbols of the other party in any  advertising,  signage,  marketing  materials,
brochures,  or any other  materials  in any  medium  without  the other  party's
express  advance  written  consent.  Any such permitted use shall be only within
guidelines  provided by such party. UUNET has approved the use of Customer's map
sent on May 25, 1999, by Customer to UUNET depicting UUNET's Services.  Customer
may revise such maps and may use such maps in its marketing materials, each in a
manner  consistent with UUNET's  approval without seeking UUNET approval of each
revision.  Any  change in the  manner or  description  of such  depiction  shall
require  prior  written  approval  by UUNET.  Changes in port speeds and circuit
locations shall not require UUNET approval.  Neither party shall issue any press
release, announcement, or public statement with respect to this Agreement or the
other party without the other  party's  express  advance  written  consent.  Any
breach of this Section shall be a material breach of this Agreement constituting
cause for termination.

                  11. CONFIDENTIALITY. The terms of this Agreement shall be held
confidential  by each party,  as shall each party's  confidential or proprietary
information  ("Confidential  Information").  The prices set forth in Schedule 1,
and any non-public data provided by UUNET to Customer  regarding  performance of
the UUNET network shall be deemed UUNET Confidential Information.  Neither party
shall  disclose the other  party's  Confidential  Information  to third  parties
without the other party's written consent,  except as permitted pursuant to this
Section. Each party shall disseminate the other party's Confidential Information
among its  employees,  Affiliates,  or agents only on a  need-to-know  basis and
shall use such Confidential  Information only for the purposes of performing its
obligations  hereunder.  To the extent a party is  required by  applicable  law,
regulation,  government agency or court order, subpoena, or investigative demand
to disclose  the  existence  or terms of this  Agreement,  or the other  party's
Confidential  Information,  such  party  shall  use its  reasonable  efforts  to
minimize such  disclosure  and to obtain an assurance  that the recipient  shall
accord confidential treatment to such Confidential Information, and shall notify
the other party  contemporaneously  of such  disclosure.  Either  party,  in its
discretion,  may  terminate  this  Agreement for cause upon ten days' notice and
without  penalty in the event of any breach of this Section.  The obligations in
this Section 11 shall survive termination or expiration of this Agreement for an
additional period of two years.

                  12.  GENERAL.  This  Agreement  may not be  assigned by either
party without the prior written consent of the other, which consent shall not be
unreasonably withheld,  conditioned, or delayed; provided, that either party may
assign or transfer  this  Agreement to any  Affiliate of such party upon advance
written  notice to the other  party.  No failure on the part of either  party to
exercise,  and no delay in  exercising,  any  right or  remedy  hereunder  shall
operate as a waiver  thereof;  nor shall any single or partial  exercise  of any
right or remedy hereunder  preclude any other or further exercise thereof or the
exercise of any other right or remedy  granted  hereby or by law. This Agreement
supersedes  all  prior  or  contemporaneous   representations,   agreements,  or
understandings  concerning  the  subject  matter  hereof.  If any  term  of this
Agreement,  or application of such term to any person or circumstance,  shall be
held invalid,  the remainder of this Agreement,  or the application of such term
to persons or circumstances other than those to which it is held invalid,  shall
not be affected thereby.


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<PAGE>

/s/ Robert McCormick                          /s/ Clint Heiden
---------------------------------             ------------------------------
Customer Authorized Signature                 UUNET Authorized Signature


Robert McCormick                              Clint Heiden
---------------------------------             ------------------------------
Printed Name                                  Printed Name


EVP/CTO                                       VP SALES
---------------------------------             ------------------------------
Title                                         Title


5/27/99                                       6/4/99
---------------------------------             ------------------------------
Date                                          Date


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<PAGE>

                         SCHEDULE 1: PRICING OF SERVICES

The  Monthly  Fees  set  forth  below  do not  apply  to any  equipment  charges
(including without limitation, routers, CSUs/DSUs, and firewall hardware), telco
installation  and line  charges,  or any other charges not included in the UUNET
Monthly Fee for a Service specified herein.


Dedicated Access Services

          Service          Start-up Charge           Monthly Fee(1)

          T-3                    N/A                      *

          OC-3                   N/A                      *


Equipment(1)
UUNET will provide  Customer  with a   *    discount off Cisco list price on any
Cisco equipment  offered by UUNET for resale and ordered from UUNET by Customer.
UUNET will provide  Customer with a   *    discount off published  list price on
any other  equipment  offered  by UUNET for  resale  and  ordered  from UUNET by
Customer.


--------
(1) For Burstable  OC-3  services:  if actual usage is under 90 Mbps the Monthly
Fee shall be     *    , and if equal to or over 90 Mbps the Monthly Fee shall be
    *    . The Monthly Fees and discounts on equipment sales set forth above are
conditioned  upon  (a)  Customer's  order,  effective  upon  execution  of  this
Agreement by Customer, of OC-3 or, at Customer's option, full 45 Mbps T-3 leased
lines and (b) Customer's  commitment,  effective  upon 30 days after  Customer's
execution  of this  Agreement,  to have on order or in service an  aggregate  of
sixteen  (16) 45 Mbps  equivalents  with at  least  one-year  terms  under  this
Agreement.  If Customer fails to order and maintain such  Services,  the Monthly
Fee for T-3 leased line Service currently in effect shall be as set forth in the
service  agreements in effect as of the date hereof and any additional  Services
shall be at UUNET's list prices in effect as of the Service order date. There is
no maximum number of circuits that Customer may order under this Agreement.



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* CONFIDENTIAL TREATMENT REQUESTED