The company that helps TV networks determine what shows get canceled or live for another season is buying the Columbia-based company that helps radio stations decide whether to change formats.

Nielsen Holdings of TV ratings fame announced Tuesday that it agreed to pay $1.26 billion in cash for Arbitron Inc., the company that measures radio audiences.

The deal brings together the largest audience research firms for two of the largest entertainment media. It gives Nielsen entry to the radio market and allows Arbitron, which largely operates in North America, to piggyback on Nielsen's global reach.

The combination will receive antitrust review from the U.S. Justice Department.

"By combining Nielsen's global capabilities and scale with Arbitron's unique radio measurement and listening information, advertisers and media clients will have better insights into consumer behavior and the return on marketing investments," William T. Kerr, Arbitron's president and CEO, said in a statement.

Arbitron's Columbia operations likely won't see significant near-term upheaval as a result of the merger, analysts said. However, Nielsen, with headquarters in New York City and the Netherlands, also said it expects to achieve at least $20 million in annual savings.

Some job losses are expected at both companies once they merge and eliminate overlap, said Daniel Moore, managing director of research with CJS Securities in White Plains, NY.

Arbitron employs nearly 1,000 full-time workers nationwide, with about 640 in Columbia and 62 in Hanover. It also employs 220-part-timers in Columbia. Arbitron also has about 251 full-time workers in India and Finland.

The company relocated its headquarters in 2009 from New York City to Columbia, where Arbitron's campus on Patuxent Woods Drive has been the heart of its survey research and data collection since 1994.

Arbitron spokesman Thom Mocarsky said it is too early to discuss what will happen with Arbitron's Maryland offices and employees.

"Nielsen will make the determination on how the companies will be best integrated after the transaction closes," Mocarsky said. He declined to comment about when that would be.

Mark Zgutowicz, senior research analyst with Piper Jaffray Cos. in Minneapolis, said he doesn't expect Nielsen to move Arbitron's operations out of Maryland in the next few years or to make other big changes that would disrupt the Arbitron culture.

"Arbitron has done a really good job of measuring radio," Zgutowicz said. "I don't see [Nielsen executives] displacing that talent and that know-how that they don't have today."

Nielsen told analysts during a conference call that it was happy to "inherit the management team of Arbitron and looked forward to keeping them in place," Moore said.

Kerr, Arbitron's CEO, announced last week that he would retire on Jan. 1. The 71-year-old will be replaced by Sean Creamer, who is currently executive vice president and chief operating officer.

Still, Howard County officials immediately reached out to both companies on Tuesday, said Laura Neuman, CEO of the Howard County Economic Development Authority.

"We will do everything on our end so that they feel welcome in Howard County and in Maryland," she said. "We sure would like to keep them here."

In a statement, Howard County Executive Ken Ulman said: "Our team will work closely with Nielsen executives to reinforce the case for why Howard County is the right place to be. We are hopeful the new owners will recognize all that we offer in terms of workforce, location and quality of life."

Nielsen agreed to pay $48 a share for Arbitron's stock. The news sent Arbitron's stock soaring Tuesday by nearly 24 percent to close at $47.03 per share in New York Stock Exchange trading. Nielsen's stock also gained 4.4 percent and closed Tuesday at $30.92 per share.

"This is an acquisition that has been talked about on and off for a number of years," Moore said. "The timing was right for both parties."