c.2013 New York Times News Service

c.2013 New York Times News Service

Nielsen Holdings announced Monday that it had completed its $1.26 billion acquisition of the radio ratings company Arbitron, a deal that Nielsen says will allow it to monitor eight hours a day of the publicís media consumption across television, radio and a range of electronic devices.

ďArbitron will allow us to analyze and understand an additional two hours of the United States consumerís day while bringing us another opportunity to provide advertisers with metrics on the effectiveness of the mediums that they advertise on,Ē David L. Calhoun, Nielsenís chief executive, said in a statement.

Arbitron, which was founded in 1949 as the American Research Bureau, will be renamed Nielsen Audio and will be integrated into Nielsenís United States Watch division, the company announced. The deal was announced in December, with Nielsen agreeing to pay $48 a share for Arbitron.

For services like Nielsen, which is best known for its television ratings but also collects data on retail spending and Internet and radio use, the crucial challenge is how to monitor and measure consumersí interactions with media outlets across various platforms, sometimes simultaneously.

One benefit for Nielsen will be access to Arbitronís Portable People Meter, a small electronic device that records all the radio signals that a person comes into contact with during the day ó an innovation that has given the radio business a much more detailed look at its listenersí habits than ever before.

The Federal Trade Commission investigated the deal because of concerns that it would decrease competition among media-tracking companies.

Last month, the agency announced a settlement that obliges Nielsen to license its data and technology ó including the Portable People Meter ó to another company for eight years. Neither the FTC nor Nielsen has announced a buyer for those services, but the most likely one is comScore, which entered into a cross-platform measurement deal with ESPN and Arbitron three months before Nielsen bought Arbitron.