June 24 (Bloomberg) -- Salesforce.com Inc. filed a patent- infringement lawsuit today against Microsoft Corp., escalating a fight between the two companies over the growing market for cloud-computing software.

Microsoft’s products such as .Net platform and SharePoint perform in a way that violates the Salesforce.com patents, and the “risk of infringement was either known or so obvious that it should have been known by Microsoft,” Salesforce.com said in the complaint.

“Microsoft has incorporated Salesforce.com’s patented technology into its services and products,” the San Francisco- based company said today in the lawsuit filed in federal court in Wilmington, Delaware.

The complaint is in response to a patent-infringement lawsuit Microsoft filed in May against Salesforce.com, which pits the world’s largest software maker against the biggest seller of Internet-based customer-management programs. Microsoft targeted Salesforce.com’s customer-relationship management software and sought a court order that would prevent the company from providing features that Microsoft claims it invented.

Salesforce.com hired David Boies, the lawyer for the U.S. Justice Department in its successful antitrust case against Microsoft, to handle the case. “Salesforce.com doesn’t comment on pending litigation, and we will let our court filings speak for themselves,” spokeswoman Jane Hynes said in an interview.

Microsoft ‘Confident’

Horacio Gutierrez, Microsoft’s deputy general counsel for intellectual property, said the company was reviewing the Salesforce.com complaint. “We remain confident in our position and will continue to press ahead with the complaint” filed in federal court in Seattle, he said.

Salesforce.com, founded in 1999, sells subscriptions to business software that runs marketing campaigns and tracks sales leads using the Internet. It competes with Microsoft’s Dynamics programs. Salesforce.com had $1.3 billion in sales last year.

The complaint seeks a court order that would prevent Microsoft’s further use of Salesforce.com products, plus unspecified cash compensation.

The earlier case is Microsoft Corp. v. Salesforce.com Inc., 10cv825, U.S. District Court, Western District of Washington (Seattle).

--Editor: Steve Geimann, James Langford

To contact the reporters on this story: Susan Decker in Washington at sdecker1@bloomberg.net; Rochelle Garner in San Francisco at rgarner4@bloomberg.net.

To contact the editors responsible for this story: Larry Liebert at lliebert@bloomberg.net; Tom Giles at tgiles5@bloomberg.net.