Siebel Systems and Dun & Bradstreet Deliver Front Office Applications with Integrated Business Intelligence.

SAN MATEO, Calif., and MURRAY HILL, N.J.--(BUSINESS WIRE)--July 27, 1999--

Siebel Systems, Inc. (Nasdaq:SEBL), the leading supplier of Web-based front office software systems, and Dun & Bradstreet (NYSE:DNB), the leader in providing business information, today announced a strategic alliance to integrate Dun & Bradstreet's (D&B) business intelligence data with Siebel Systems' Web-based front office applications.

Marketed as the Siebel D&B Integration Solution, this new module within the Siebel Front Office Applications Suite enables customers to access D&B's in-depth market data -- covering more than 26 million organizations around the world -- from within Siebel Systems' sales, marketing and customer service applications.

The Siebel D&B Integration Solution provide users with the most comprehensive business information about customers and prospects available. Using the D-U-N-S(R) Number, a unique company identifier that D&B assigns to each business entity, customers can be assured that extensive, relevant company data is retrieved for each customer and prospect. Using the Siebel D&B Integration Solution, organizations can now:

--   Instantly profile an entire organization to understand its
     history, location, size, products and services to target and
     qualify prospective customers and determine territories;

--   Quickly obtain information about a company's structure to
     identify key decision makers and navigate the organization's
     family tree to understand all of the inter-relationships among an
     organization's parent company and its subsidiaries and
     affiliates;

--   Easily create more targeted marketing lists to reach the right
     organizations and individuals, improving the overall
     effectiveness of marketing campaigns and;

--   View an organization's credit background to understand its fiscal
     history and help reduce credit risks by linking directly to D&B
     reports.

"Dun & Bradstreet is the clear leader in business intelligence," said David Schmaier, senior vice president, products, Siebel Systems. "This alliance underscores the importance of integrating D&B's world-class business information into Siebel Systems Front Office Applications to allow our customers to better profile and navigate an organization and to create more effective marketing campaigns."

In collaboration with Siebel Systems, D&B also offers Data Rationalization Services that consolidate, cleanse and eliminate redundant account and contact records. Using D&B's Data Rationalization Service, customers can consistently ensure data quality and integrity.

"Companies rely on Dun & Bradstreet to provide the insight they need to help build profitable, quality business relationships with their customers, suppliers and other business partners. D&B information provides the critical business intelligence that fuels companies' decisions in the supply and demand chain," said John Bunyan, senior vice president, marketing, Dun & Bradstreet-U.S. "Siebel Systems' customers can now tap into the valuable D&B information embedded in their enterprise solutions to get intelligent information on individual companies, or to obtain lists of prospects that meet the criteria they specify."

Dun & Bradstreet's company information will also be included in Siebel Systems' Web-based customer intelligence solution, Siebel InterActive, which uses sophisticated software agent technology to automatically gather relevant information for individuals from sources inside and outside their own organizations. The resulting information is delivered to their desktop in the form of dynamic, personalized ActiveBriefings, which provide relevant, business-critical information tailored to the specific needs of sales, marketing and customer service professionals.

Siebel Systems and D&B plan to use each other's products internally.

About Dun & Bradstreet

Dun & Bradstreet (D&B), a company of The Dun & Bradstreet Corporation (NYSE:DNB), is the world's leading provider of business credit, marketing and purchasing information and receivable management services. Companies of all sizes in all industries around the world use D&B information in their supply and demand chains. By integrating D&B information into business systems and processes, companies can better manage their customers and suppliers and achieve a direct and seamless link between back-office and front-office operations. The Dun & Bradstreet Corporation, which also includes Moody's Investors Service, is headquartered in Murray Hill and employs approximately 12,500 people in 37 countries with majority-owned entities. It reported 1998 revenue of $1.93 billion. Additional information about Dun & Bradstreet is available through its Web site: www.dnb.com.

About Siebel Systems

Siebel Systems, Inc. (Nasdaq:SEBL) is the world's leading supplier of Web-based front office software systems. Siebel Systems provides an integrated family of sales, marketing and customer service application software for field sales, customer service, telesales, telemarketing, field service, third-party resellers and Internet based eCommerce and self service. Siebel Systems' products are designed to meet the needs of small, medium and large businesses. Siebel Systems' sales and service facilities are deployed locally in more than 20 countries and can be reached through the World Wide Web at www.siebel.com.

Except for the historical information contained herein, this press release contains forward-looking statements that involve risks and uncertainties. The success of the agreements and products described above and the future operating results of Siebel Systems, Inc. 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 Enterprise Relationship Management markets, dependence on the Internet, risks associated with new versions and new products and risks associated with rapid technological change. Further information on potential factors that could affect the financial results of Siebel Systems, Inc. are included in Siebel Systems, Inc.'s Report on Form 10-Q for the fiscal quarter ended March 31, 1999 and its other filings with the Securities and Exchange Commission.

Note to Editors: Siebel is a trademark of Siebel Systems, Inc. and may be registered in certain jurisdictions. Dun & Bradstreet, D&B, D-U-N-S and all other D&B product or service names referenced herein are trademarks, registered trademarks or servicemarks of The Dun & Bradstreet Corporation. All other product and company names mentioned are the property of their respective owners and are mentioned for identification purposes only.