The long-running standoff between Nielsen Media Research and America's television industry is set to reach its climax at a specially convened Senate hearing next month.
The row revolves round the VNU-owned researcher's Local People Meter ratings service which critics claim is flawed because it under-represents black and Hispanic audiences.
Nielsen has fought a rearguard action against the claims by its main opponent the Don't Count Us Out coalition which is a loose coalition of Hispanic media groups. Sceptics maintain one of the driving forces behind the coalition is Rupert Murdoch's Fox TV network.
For its part the coalition hailed the July 15 hearing as an "historic step by Congress towards ensuring fairness and accuracy in media ratings."
Nielsen, which was planning to introduce LPMs to Los Angeles next month as the final part of the system's roll-out to the biggest metropolitan markets, said it hadn't yet been notified of the inquiry.
A spokesman, however, said the company was looking forward to "an open and candid discussion of the issues."
Data sourced from: AdWeek.com; additional content by WARC staff