(Updates with closing share price in fifth paragraph.)

Dec. 20 (Bloomberg) -- Nuance Communications Inc. agreed to buy Vlingo Inc. in a deal that gives the developer of voice- command technology a system that can respond to spoken words with actions such as Internet searches.

Terms of the acquisition weren’t disclosed in a statement today from Nuance, based in Burlington, Massachusetts, and Vlingo, a closely held company backed by Charles River Ventures Inc., Sigma Partners LP, Yahoo! Inc. and AT&T Inc.

The companies are combining after fighting legal battles over patent claims. The purchase will help capture rising demand for voice-command technology, which is being driven by devices such as Apple Inc.’s Siri, Nuance said.

“Our companies are stronger together than alone,” Dave Grannan, chief executive officer of Cambridge, Massachusetts- based Vlingo, said in the statement.

Nuance rose 7 percent to $25.63 at 4 p.m. New York time, for the shares’ biggest gain since Oct. 6. They have advanced 41 percent this year.

--Editors: John Lear, Niamh Ring

To contact the reporter on this story: Beth Jinks in New York at bjinks1@bloomberg.net

To contact the editor responsible for this story: Peter Elstrom at pelstrom@bloomberg.net