Enterprise Customers Extend Services With USi.

Business/Technology Editors

ANNAPOLIS, Md.--(BUSINESS WIRE)--July 30, 2001

USinternetworking, Inc. (USi, Nasdaq: USIX), the leading Application Service Provider (ASP), today announced that several enterprise customers have chosen to significantly broaden their existing relationship with USi by purchasing multiple services or significantly upgrading their existing contracts.

"USi has consistently demonstrated an ability to deliver high quality ASP solutions and has helped to alleviate many IT challenges," said Susan Fisher, Director, Financial Projects, Blue Cross Blue Shield of Michigan (BCBSM). "Based primarily on the great results achieved through our original division engagement, BCBSM decided to roll out a human resources and financial management solution across our entire organization."

Among the large numbers of USi clients that have recently chosen to renew and expand their services are:

--A division of Blue Cross Blue Shield of Michigan, the largest of the single-state affiliates, now receives USi's Financial Management Solution Powered by PeopleSoft. BCBSM recently signed on to receive USi's Human Resources Solution & Financial Management Solution Powered by PeopleSoft for their entire organization.

--Mars Music, one of the nation's largest sellers of musical instruments, recording equipment and pro audio gear, significantly upgraded its USi Financial Management Solution.

--Wood Mackenzie, a subsidiary of Deutsche Bank AG that provides consultancy services to the Energy and Life Sciences industries, has signed a 3 year contract extension, extending the support provided by USi from hosting support to a managed application service for BroadVision.

--USi client XL Global Services, part of XL Capital Ltd, one of the world's leading insurance, reinsurance and financial solutions providers, has signed on for USi's Human Resources Solution Powered by PeopleSoft. XL Capital Ltd currently employs USi's Financial Management Solution Powered by PeopleSoft.

"USi's many enterprise clients recognize the strength of the ASP value proposition and USi's ability to deliver, and we thank them for their ongoing business," said Andrew A. Stern, CEO, USinternetworking, Inc. "The high percentage of our client base that chooses to purchase multiple services or upgrade existing service is testament to the great return on investment being realized."

USi clients benefit from USi's architecture including comprehensive network infrastructure and monitoring, failover services and data centers. In addition to receiving an industry-leading Service Level Agreement (SLA), USi's clients also receive best-practices implementation, consulting, hosting, management and 24x7 client services support. The Company was recently named the ASP global market leader by market research firm IDC.

About USinternetworking, Inc.

USinternetworking Inc., the leading Application Service Provider, delivers enterprise and e-commerce software as a service. The company's iMAP portfolio of service offerings delivers the functionality of leading software from Ariba, BroadVision, Lawson, Microsoft, Oracle, PeopleSoft, Plumtree and Siebel as a continuously supported, flat-rate monthly service via an advanced, secure global data center network. Additionally, USi's AppHost managed application hosting services provide the most advanced solutions for enterprises, software companies, marketplaces, and system integrators that are seeking a better way to deliver solutions over the Internet to their customers and end users.

Internet Managed Application Provider, iMAP, AppHost, PriorityPeering, USiGSP, USiSAN USiAccelerate, and Making Software Simple are service marks of USinternetworking, Inc. All other trademarks are the property of their respective owners. USi strategic partners and providers are publicly traded on Nasdaq under the symbols: ARBA, BVSN, CSCO, MSFT, ORCL, PSFT and SEBL.

Information in this release may involve expectations, beliefs, plans, intentions or strategies regarding the future. These forward-looking statements involve risks and uncertainties. All forward-looking statements included in this release are based upon information available to USinternetworking Inc. as of the date of the release, and we assume no obligation to update any such forward-looking statement. The statements in this release are not guarantees of future performance and actual results could differ materially from our current expectations. Numerous factors could cause or contribute to such differences. Some of the factors and risks associated with our business are discussed on the Company's Form 10-K filed with the SEC on April 2, 2001, its 10-Q filing on May 15, 2001, and in our other reports filed from time to time with the SEC.