NEW YORK (Bloomberg) - Sun Microsystems Inc., the world's third-biggest server maker, agreed to acquire Vaau Inc. to gain programs for computer security.

Vaau, based in Torrance, California, develops software that helps companies determine the information their employees can obtain through corporate networks. The company's name means "wind" in Hindi.

The Vaau acquisition builds on Sun's purchase of identity software provider Waveset Technologies Inc., four years ago. Security and access are fast-growing software markets, fueled by regulatory requirements including the Sarbanes-Oxley Act of 2002.

"Companies need to know and report who can access and see what information," said Jim McHugh, Sun's vice president for software and infrastructure marketing.

Vaau's products identify an individual by role, such as a job title or function, and provide access accordingly. Identifying people by role, rather than by name, makes it easier to adjust access as they move from job to job or leave a company, said Paul Velusamy, Vaau's vice president for marketing.

Sun doesn't break out software revenue. Servers, computers used to run corporate networks and Web sites, account for almost half of the company's revenue. Services and storage, buttressed by the $4.1 billion purchase of Storage Technology Corp. in 2005, account for the rest.

The transaction, the third Sun has announced this year, should close during the first three months of 2008, the Santa Clara, California-based company said yesterday. Terms were not disclosed. Most of Vaau's 90 employees will be retained, said Kristi Rawlinson, a Sun spokeswoman.

Sun Microsystems rose 74 cents, or 3.6 percent, to $21.25 in Nasdaq Stock Market trading.