DTS Inc. completed on Monday its previously announced acquisition of iBiquity Digital Corp., a developer for high-definition radio technology, in a deal valued at $172 million.

DTS, a Calabasas company that makes high-definition audio equipment for mobile devices and cinemas, sees the acquisition as the portal into the car audio market. iBiquity develops technology that allows AM/FM broadcasting to upgrade from analog to digital in order to provide improved sound quality. About 35 percent of cars sold in 2014 in the U.S. had built-in HD radio technology, and DTS believes this market will expand, the company said in its announcement.

“This acquisition bolsters our prospects for attractive, long-term growth by increasing our footprint in the broadcast and automotive spaces and adding key IP and technology to our portfolio,” Jon Kirchner, chief executive, said in a statement.

Shares closed up $1.84, or 6.8 percent, to $28.75 on the Nasdaq.