A television industry group Thursday withheld its approval from Nielsen Media Research's new system for measuring viewership in New York, sources said.
The decision by a subcommittee of the Media Rating Council hands a victory of sorts to News Corp., Univision Communications Inc. and activist groups trying to delay the June 3 rollout of "people meters" in New York.
Nielsen does not need the group's approval to move forward. But the subcommittee's action is one more setback for Nielsen's controversial plans to overhaul its antiquated system for gauging viewership -- data that help set advertising rates.
Nielsen plans to adopt the system in Los Angeles in July.
News Corp.'s Fox TV stations and Spanish-language broadcaster Univision claim the new system produces biased results. Preliminary use of the system has shown a ratings drop for their stations.
The companies argue that Nielsen's sample audience for its "local people meter" system does not accurately reflect the region's makeup of Latinos and African Americans.
Nielsen executives dispute the charges, saying the people meters provide more accurate ratings. They cite preliminary results that have shown that some networks and cable channels, including Viacom Inc.'s Black Entertainment Television, get a ratings boost.
People meters are electronic boxes wired to a TV set that automatically record viewing. Viewers who are part of Nielsen's sample audience punch buttons on a remote control to provide instant and detailed information about who is watching.
Although Nielsen has been using people meters to generate its national overnight ratings since 1987, the firm is only now trying to switch to the system in local markets to replace the 1950s-era paper diaries.
It was unclear whether Thursday's decision would prompt a delay of the rollout in New York.
"We haven't received anything official from the Media Rating Council," Nielsen spokesman Jack Loftus said. "It's our understanding that the accreditation process is continuing."
Times staff writer James Bates contributed to this report.