A suit by 99 Washington Post reporters, editors and photographers who are seeking overtime pay probably will not be resolved quickly, a federal judge said yesterday, because the suit involves complicated issues of individual creativity, originality and artistic ability.

Lawyers for The Post and the employes had sought an expedited ruling in the case, but U.S. District Judge Gerhard A. Gesell said the issues might have to be determined on an employe-by-employe basis by 99 trials involving several judges and juries "all over the courthouse."

The suit is one of two such cases that are being watched closely by the newspaper industry because of their financial importance and the potential impact on newsroom management. The other, brought by the federal government against The Concord Monitor in New Hampshire, is awaiting decision by a judge who has been considering the case since the trial ended in June 1986.

Gesell said yesterday that the suit could have a profound effect on The Post's future. If the employes are successful in forcing the Post to pay overtime, he said, there would be "a change in base pay, a change in assignment methods {and} a change in the requirement to be in the office."

"It's a wholly different ball game; it's a wholly different newspaper," Gesell said. "It's going to hurt the newspaper as well as some of the reporters."

The newspaper's policy is to pay overtime to employes who work more than 37 1/2 hours in a week only if the employe's base salary is less than $810 a week. Most of the newspaper's reporters, editors and photographers earn more than that amount.

Federal law requires employers to pay a 50 percent overtime premium for each hour worked in excess of 40 hours a week. The law exempts executive, administrative and professional employes.

The Post has maintained that reporters are professional employes because they fall within the legal definition of "artists," whose work is predominantly original and creative.

The reporters have argued that although there is a considerable intellectual aspect to their work, they are not ordinarily engaged in writing that is predominantly "original and creative."

The employes filed suit against The Post on Oct. 1, 1986, claiming that the newspaper had improperly refused to pay overtime for hours worked in excess of 40 each week.

The issue of overtime compensation has been a pointed one during recent negotiations between The Post and The Newspaper Guild. In August, The Post declared its talks with the union to be at an impasse and instituted its last wage offer, under which higher paid employes received weekly raises of more than $90.

Post officials said the average salary for reporters was more than $50,000 a year before the August raise. According to figures compiled by the Guild, the average salary for Post reporters is $1,071 a week, or $55,692 a year.

Average salaries for other newsroom employes -- including assignment editors, copy editors and photographers -- are lower.

Gesell said that it might be necessary to examine plaintiffs individually to determine whether their work assignments are creative and imaginative in nature.

"I have great difficulties in assuming that any generalities can decide this case," Gesell said, noting that although there were no general academic requirements for reporters, some of the 99 plaintiffs were hired because the newspaper needed someone with a particular academic background.

"I point that out to show you how difficult it is to deal with this in a cosmic way," he said.

Robert Paul, an attorney for the reporters, told Gesell that normal reporting primarily involves fact gathering and that unless the employe engages in writing opinion or criticism, the work is not considered "artistic" under federal law.

Gesell challenged Paul to distinguish between factual reporting and editorializing in The Post's news sections. "When you read the front page of The Washington Post, you're not getting facts . . . I've been reading that rag for a long time," Gesell quipped. "There is considerable editorializing on the front page."

Paul countered that Post policy is to label each article that contains the opinions and conclusions of the reporter with a "news analysis"tag.

John G. Kester, an attorney for the newspaper, told Gesell that most of the 99 cases could be decided by examining records already developed through pretrial discovery.

Kester said that depositions given by Leonard Downie Jr., The Post's managing editor, and by reporter Tom Sherwood, the lead plaintiff, say essentially the same thing about what reporters do.

Quoting Sherwood, Kester said, " 'We are reporters, not tape recorders.' I think that says it well."

After the hearing, Sherwood, chairman of The Post's Guild unit, said there was limited room at the newspaper for creativity within the news sections. Said Sherwood, "The most creative reporter we've ever had was Janet Cooke, and she was fired. And rightfully so."

Cooke was fired in 1981 after admitting that she falsified a Pulitzer Prize-winning report on a child's heroin use.