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Siebel Systems
www.siebel.com

SAN MATEO, CA., June 10, 2002 - Siebel Systems, Inc. (Nasdaq: SEBL), the world's leading provider of eBusiness applications software, today announced that HEW, a leading German energy provider, is experiencing an increase in sales using Siebel eEnergy?a comprehensive suite of eBusiness applications designed specifically for the energy industry. By creating a single, comprehensive view of customer information across multiple channels and integrating with the company's back office applications, Siebel eEnergy is also enhancing customer satisfaction and improving productivity.

By uniting customer information over multiple channels, including face-to-face contact and telephone communication, HEW offers customers personalized energy contracts. Through improved management of energy contracts, HEW has lowered its overall energy costs. This strategy uniquely positions HEW to increase sales efficiency, accelerate the service delivery process, and enhance customer satisfaction and loyalty.

Through integration with the company's legacy pricing application and billing systems, Siebel eEnergy enables HEW to manage complex sales contracts and service agreements. To create a new account, a salesperson captures and records a significant amount of information about the customer, including the energy services and equipment the customer is currently using, the infrastructure on the premises, and the amount of energy the customer is currently using. HEW's pricing desk can then quickly and efficiently prepare a "costing" for the account, using templates and standard terms and conditions where necessary. The sales and pricing representative then drafts a pricing plan that best suits the individual needs of the customer. Once the customer has reviewed and approved the plan, the representative prepares and forwards the contract into the billing system.

A central repository of customer information is also assisting HEW's 250 sales and service professionals to enhance the delivery of services to customers, increase customer satisfaction, and maximize loyalty. HEW can better track its network assets and prequalify service orders for new customers. The view of billing transactions allows HEW to track customer billing information, payment history and query billing information from billing systems.

"The enhanced customer understanding, contract management, and service delivery means we have greater 'share of wallet' of our customers, they receive a better service, and customer churn has been reduced," says Klaus Rockel, head of Online Marketing and Customer Management, HEW. "Through integration with our billing systems, our staff can quickly generate customer pricing plans and contracts. This functionality increases sales efficiency and accelerates the service delivery process."

More than 1.2 million residential and business customers in the Northern region of Germany rely on HEW for their energy provision. The company, which is a wholly owned subsidiary of the Swedish company Vattenfall, is headquartered in Hamburg.

About Siebel Systems
Siebel Systems, Inc. is the world's leading provider of eBusiness applications software. Siebel Systems provides an integrated family of eBusiness applications software, enabling multichannel sales, marketing, and customer service systems to be deployed over the Web, in call centers, in the field, through reseller channels, and across retail and dealer networks. Siebel Systems' sales and service facilities are located in more than 32 countries. For more information, please visit Siebel Systems' Web site at www.siebel.com.

Except for the historical information contained herein, this press release contains forward-looking statements that involve risk or uncertainties. Future operating results of Siebel Systems may differ from the results discussed or forecasted in the forward-looking statements due to factors that include, but are not limited to, risks associated with customer relations, such as the availability of Siebel Systems' products and services, customer implementation of products and services, relationships with customers, third-party vendors and systems integrators, concentration of revenues in a relatively small number of customers, existence of errors or defects in products, ability to successfully manage growth, significant current and expected additional competition and the need to continue to expand product distribution and services offerings. Further information on potential factors that could affect the financial results of Siebel Systems are included in Siebel Systems' Annual Report on Form 10-K, Quarterly Reports on Form 10-Q and its other filings with the Securities and Exchange Commission, which are available at www.sec.gov. Siebel Systems assumes no obligation to update the information in this press release.

Siebel is a trademark of Siebel Systems, Inc. and may be registered in certain jurisdictions. All other product and company names mentioned are the property of their respective owners and are mentioned for identification purposes only.

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