The National Association of Broadcasters announced yesterday that it has stopped enforcing its voluntary advertising standards that limit the number of commercials a television station may broadcast every hour.

As a result of a recent federal court ruling that found part of the NAB advertising code in violation of the nation's antitrust laws, the NAB's executive committee decided at a special meeting to stop scrutinizing television programming to make sure stations devote no more than 9 1/2 minutes of each prime-time evening hour to commercials.

The NAB said it immediately will appeal the ruling by U.S. District Judge Harold H. Greene that the code is anticompetitive because it limits the number of products that can be promoted during a single commercial.

The NAB said it "believes that the District Court's decision is wrong and does not recognize the very strong public interest served by the television and radio codes and by broadcaster self-regulation."

Nonetheless, it concluded, given the uncertainties of the court's ruling, the NAB no longer could make sure all of its members were complying with the code.

The action goes far beyond the court order that directed the NAB to stop enforcing its rule that says no more than one product can be promoted in any commercial lasting less than 60 seconds. It also terminates the NAB's code limiting the number of commercials each hour and the number of consecutive commercials. Under Greene's decision, these rules could have stood, even though the judge called a trial on the provisions. The Justice Department has charged that these limits are anticompetitive because they restrict the supply of commercial television time, thereby driving up advertising prices to the ultimate detriment of consumers.

For Washington area viewers, the NAB's action should bring no immediate changes, some television station managers said last night. "I can't imagine us making any changes as far as advertising is concerned," said Bill Haight, national sales manager for WJLA-TV, Channel 7, noting that, in many cases, the station runs fewer advertisements than the maximum permitted by the code.

"We'll continue business as usual," said Ronald Townsent, station manager for WDVM-TV, Channel 9.

Although voluntary, the code is followed closely by most of the nation's television stations. Stations that don't comply are unable to use the association's seal of approval.