New York-based media measurement, ratings and research provider, Nielsen, has announced its acquisition of San Francisco-based Telephia, the leading provider of syndicated consumer research to the telecommunications and mobile-media markets for an undisclosed sum.

The acquisition will strengthen its wireless measurement technology and expertise, while also allowing it to offer measurement services to the mobile sector.

Earlier this month Nielsen had announced the launch Nielsen Wireless, its wireless measurement service. Nielsen Wireless will use data from its existing ''national people meter'' TV panel to help mobile media firms position their offerings and identify how customers of different mobile operators consume media at home.

"It''s not clear what consumers are going to be doing over the next ten years with their cell phone and the Internet. We''ve been doing a lot of research in this area," said Jesse Goranson, senior vice president of account management for Telephia.

He said that with the increasing use of mobile communication devices for content and communications, the acquisition of Telephia would help Nielsen track more accurately mobile and wireless trends. Goranson added.

"To the extent that there are a lot of amazing new data services on the cell phone, that''s an area where we''ve been doing a lot of research and have expertise and will be complimentary to the work that Nielsen is doing," said Goranson.

He also predicted advertisers and marketers will benefit from an increased level of metrics and measurement that the combined companies can provide regarding wireless campaigns.

"There are quite a few brands making commitments and experimenting with advertising on mobile phones. [But] for advertising to take off in the mobile arena, there needs to be measurement. There needs to be a definition of what is successful in this sector," Goranson said.

"The promise of Nielsen and Telephia is we will be able to give folks an understanding of what is working and what is not. We want the folks to be able to do the same things on the mobile phone that they are doing on the web and television and have metrics."

The acquisition is subject to regulatory approval and expected to close later this year. Telephia will remain at its San Francisco headquarters with its current management team. A decision on whether Telephia will be rebranded following the acquisition, has yet to be taken.