Twenty years ago, all of the minority journalists in America probably could have squeezed into a medium-sized college lecture hall. A 1968 study estimated that only 400 minority reporters had jobs on America's 1,700 daily newspapers.

Last week, a hefty percentage of the minority journalists working on U.S. dailies gathered at the Baltimore Convention Center for the 10th annual convention of the National Association of Black Journalists. Veteran reporters who had skipped the last couple of conferences were pleasantly surprised to note that their numbers had risen to 3,080, an increase of more than 650 percent.

The minority journalists had come a long way, and so had the newspaper industry.

But there is another side of the story that is painful for the journalists and embarrassing for the newspaper industry. It is that minority journalists seldom rise to management positions in newspapers.

Furthermore, large numbers of minority reporters do not believe the industry will ever provide them with that opportunity.

In a survey released last week, the Institute for Journalism Education reported that the lack of opportunity for minority journalists constitutes a "quiet crisis" in American newsrooms.

"The desire [to be managers]," wrote Ellis Cose, the institute's president, "seems to be linked to the aspirations of many minorities to effect change both within and outside the profession."

Noting that minority women, in particular, desire careers in management, the study found that they are the least likely of all groups to be given managerial responsibilities.

"The press helped to push civil rights onto the nation's agenda," Cose said, "but newsroom equality has been embarrassingly slow in coming."

The journalism profession, which writes about the hopes and frustrations of others, has fallen far short of its own goals. The American Society of Newspaper Editors (ASNE) predicted in 1978 that the percentage of minorities in the nation's newsrooms would be equivalent to their percentage of the population by the year 2000, and subsequently many top executives declared that they were going to do something about it -- and did.

But according to ASNE figures, minorities constitute less than 6 percent of the journalists employed in newsrooms; fewer than 40 percent of the nation's newspapers employ any black, Hispanic, Asian or Native American journalists at all.

With that in mind, about 40 percent of the minority journalists interviewed in 10 cities told the Institute for Journalism Education that they expect to leave journalism because of this lack of opportunity for advancement.

That would be a setback for the country as well as the journalists.

"The news industry can only make sense of the American experience if it truly understands it," Cose observed. "And the better [the industry's] composition reflects the complexity of the population, the more likely it becomes that it will understand -- and tell -- all of America's story."

As a minority journalist, I have applauded the increase of black, Hispanic and Asian reporters and editors in newsrooms.

Having served as chair of the Institute for Journalism Education's board, I have read the statistics and examined the problem closely.

Among the big urban newspapers where the staffs are relatively integrated, executives have yet another challenge: to recognize and promote the most talented potential managers from among the ranks of minority journalists.

And if that continues to fail to happen, the losers won't just be minority reporters and editors or newspapers themselves. The losers will be the readers who yearn for a fuller portrayal of a diverse America.