Industry ratings body Barb has appointed TNS to handle the contract to measure TV audiences, replacing AGB Nielsen, which is 50% owned by Sir Martin Sorrell's WPP.

Barb, the organisation backed by the BBC, ITV, Channel 4, Channel Five, BSkyB and the Institute of Practitioners in Advertising, has made the appointment with the intention of developing a system that will be adaptable to digital television.

The TV ratings body has awarded TNS with two contracts that will run for six years from January 1 2010.

TNS has been tasked with establishing the new Barb viewing panel and handling meter panel installation, data retrieval, processing and audience reporting functions.

The new system aims to measure news trends such as time-shifted viewing, encompassing video-on-demand services such as 4oD that are watched via TV sets.

Barb already reports time-shifted playback from video recorders, personal video recorders such as Sky+, and DVD recorders.

The ratings body also expects to trial PC monitoring and, possibly, extend this to laptops and "transportable devices" in the future, with a view to including this data in its audience panel.

Today's appointment has been mired in controversy with Nielsen, the joint venture partner in AGB Nielsen, reportedly threatening to take legal action over patents related to measurement products TNS plans to use.

"Barb has considered numerous innovative proposals over a rigorous 16-month tendering process," said the organisation's chief executive, Bjarne Thelin.

The ratings body has awarded four contracts in total. Survey design, quality control and calculation methodology has been awarded to RSMB in an "increasingly future-facing role to consider new televisual distribution routes".

Barb's establishment survey, which gathers information on the total UK television-owning population, has been awarded to Ipsos Mori.

The AGB Nielsen Media Research managing director, Justin Sampson, said: "We are naturally disappointed that Barb do not share our vision for how our system will continue to deliver audience measurement for all forms of viewing across all platforms."

David Lowden, the chief executive of TNS, said: ''Barb's decision demonstrates TNS's market leadership in audience measurement. We're delighted to be reappointed.''

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