Black Americans must resume direct pressure tactics on television networks, newspapers and the film industry, as they did during the 1960s to ensure that blacks are portrayed accurately, a panel of blacks in the news media said yesterday.

"Unfortunately for us as a people, blacks are a trend in television and print journalism ; one minute we're in, and then, like hula hoops, we are out," said Stan Myles, program executive for motion pictures for television at CBS. He mentioned the spate of television shows featuring blacks in the wake of the success of the Bill Cosby show.

"We have to get around being a trend," he said. "We have to be a pressure group they have to deal with every day, like the women's pressure group and the gay pressure groups. We have to make them care."

His sentiments were echoed by print journalists. Reginald Stuart, a journalist at The New York Times, suggested that blacks should investigate what became of, and perhaps reconstitute, groups that were pressuring the media in the '60s to improve their portrayal of blacks.

Stuart noted that a recent survey of black journalists in television and newspapers found nearly half considering leaving their jobs because they think that blacks have no future in the profession.

Dwight M. Ellis, vice president of the National Association of Broadcasters, said the Reagan administration's opposition to affirmative action has been a signal to whites in broadcasting and journalism that they no longer have to make special efforts to treat blacks equitably.

"There is not much more we can do legislatively," Ellis said. "We have to get back to grass-roots tactics, pressure tactics."

Myles, Stuart and Ellis participated in a panel at the opening of the Congressional Black Caucus Foundation's legislative weekend.

In a later interview, Ellis said black Americans have to recall that "power yields nothing without a demand. And for black Americans to apply more pressure to television and newspapers is in the American scheme of things; it is doing business."

Ben Johnson, assistant managing editor for development at the Detroit Free Press, said he is "excited and frustrated" at the hiring of black journalists. On one side, Johnson said, Jay Harris is executive editor of the Philadelphia Daily News and Curtis Riddle is managing editor of The Cincinnati Enquirer. But the number of black journalists is still declining. Less than 1 percent of newspaper management is black. And less than 5 percent of journalists are black, he said.

In a separate session on blacks in corporate America, Regina Nixon of the National Urban League said she has found that 13 percent of black managers think that they have "high" potential for advancement.

Glegg Watson, co-author of a book on blacks in corporations, said many blacks are afraid to acknowledge racism in a corporate setting. He said many of those blacks try to deny their color, their gender and ethnicity in order to fit in, but he said there "is no proof that they will be more successful if they are less black."