Fox TV, Univision and other critics of the way local television audiences are measured told Congress on Thursday that minorities are being undercounted and that could lead to the elimination of shows popular with blacks and Hispanics.

The chief executive of Nielsen Media Research (search) said the company has hired more people and improved training to encourage greater minority participation. Susan Whiting added that critics simply may be worried about ratings.

Nielsen, an independent company based in New York, tallies viewership for the networks. These ratings often are the basis for decisions about whether to renew or drop shows and are used to set advertising rates. A show that does well in the ratings can charge a premium price for commercials.

"The TV ratings system upon which we rely is seriously broken," said Thomas Herwitz, president of station operations for Fox Television Stations. "Accurate ratings are crucial to making programming decisions and meeting community needs."

He said there needs to be system of checks and balances over Nielsen "to protect the public."

Whiting said the real problem is that some media companies fear the company's new counting method will produce lower ratings for their shows, and in turn, less advertising money.

"We will continue to resist all attempts to manipulate this process to mislead the public through a campaign that has nothing to do with protecting the rights of African-Americans (search), Latinos and Asian- Americans, or any other ethnic group," Whiting said.

Nielsen counts viewership on a national level by choosing a sample of homes and supplying "people meters" that record viewing habits.

In some local markets, the meters are replacing handwritten diaries kept by "Nielsen families." Different households are used for the national and local measurements.

Nielsen said the meters give a more accurate reading of what people are watching because they register what is on a television at any given time; the diaries require honesty and a good memory.

"The American public has a clear and compelling interest in ensuring that the television ratings system is as fair and accurate as possible," said Sen. Conrad Burns, chairman of the Senate Commerce, Science and Transportation subcommittee that held the hearing.

After the hearing, Burns said the parties should be able to resolve the dispute without any congressional intervention.

But during a conference call with reporters later, Burns, R-Mont., said legislation may become necessary if Nielsen does not address concerns about minority representation.

Nielsen has used the meters since 1987 to gather national ratings data. It decided in the past few years to use the electronic boxes in the top markets. Then the complaints began.

Meters in New York and Los Angeles showed big differences in viewership when compared with the diaries. Some programs popular with minorities dropped sharply in the ratings.

Critics say Nielsen has not worked hard enough to build samples that accurately reflect the diversity of big cities. They point to data showing recorded black viewership of all programming for the 7-8 p.m. hour in New York fell by 32 percent when the meters replaced paper ballots.

Fox's parent company, News Corp. has helped underwrite a campaign against the new counting method.

Nielsen began using the meters locally in Boston two years ago, and New York and Los Angeles this summer. Plans call for the meters to be used in Chicago next month, San Francisco in September, and then Detroit, Washington, Dallas and Philadelphia next year.

Last month, the independent Media Rating Council decided not to recommend accreditation of the new service in New York. The council, an association of television, radio and advertising agencies, said it has concerns about the way minorities are classified under the system.

Nielsen eventually wants to include data from many of the participants in the local measurements in the national sample the company takes. Critics suggest the national numbers will show the same viewership drops seen in the cities.

News Corp. is the parent company of the Fox News Channel, which operates FOXNews.com.