Business Editors and High-Tech Writers

CUPERTINO, Calif.--(BUSINESS WIRE)--June 26, 2001

Portal Software, Inc. (Nasdaq:PRSF) a leading provider of business infrastructure software for next-generation communications services, announced today that Infranet, its customer management and billing platform, has been implemented by Spanish ISP and Internet portal eresMas Interactiva S.A. With more than 40 percent of the Spanish Internet market, eresMas will use Infranet to serve two million users and to deploy new value-added services.

eresMas provides dynamic customized portals for residential customers. Launched in March 2000, eresMas offers innovative services and content accessible through multiple platforms including PCs, mobile phones and television. Over the last year, eresMas has become one of the most highly regarded Internet companies in Spain by successfully offering differentiated services.

To support its new service offerings and evolve beyond the company's original free and flat-rate charging schemes, eresMas required a highly flexible real-time customer management and billing platform. In addition, the new valued added-services and support for virtual ISPs had to be introduced seamlessly and effectively, which lead to the selection of Infranet.

"Infranet's flexibility will enable eresMas to develop real-time pricing models to support the frequent pricing and promotion changes necessary in a highly competitive environment. Apart from the usual per-user or per-month billing methods, other value-based charging mechanisms can be introduced including; billing for content, private branding, access time, number of transactions, or bandwidth used. Infranet provides the powerful customer management and billing solution that eresMas needs to support its rapid expansion into new business markets," commented Ian Perry, Vice President EMEA, Portal Software.

eresMas has implemented Infranet 6.0 running on Sun platforms under UNIX, which includes innovative functionality allowing eresMas to provide private branding across all service offerings.

About eresMas

eresMas Interactiva S.A. (www.eresmas.com), formed in March 2000, is the Internet company of Auna (www.auna.com), Spain's first integrated telecommunications operator, whose reference shareholders are Endesa, Telecom Italia, Union Fenosa and other finance partners. It offers customised portals and multiple platforms for residential, cable TV companies and virtual ISP customers. With more than 40 percent of the Spanish Internet market, eresMas already has approximately two million users.

About Portal Software, Inc.

Portal Software provides software to manage next-generation communications and e-services. The Infranet software platform enables service providers to rapidly deploy new services, define optimal business models and price plans, and bill their users. Portal's software is licensed by more than three-quarters of the world's 25 largest communications services companies to support wireless, broadband Internet, next-generation voice, and other e-service offerings. Customers include AOL Time Warner, Reuters, Qwest Communications, Sprint, NTT, Deutsche Telekom, Telenor Mobil AS, China Telecom, and France Telecom and Akamai Technologies, Inc. Portal Software employs over 1,500 people at more than 40 offices worldwide. For more information, visit www.portal.com.

Note to Editors: Infranet is a U.S. registered trademark, and Portal and the Portal logo are trademarks of Portal Software, Inc. All statements made in this press release are made only as of the date set forth at the beginning of this release. Portal undertakes no obligation to update the information in the event that facts or circumstances subsequently change.