An NAACP study found that minorities and women are "virtually excluded" from the ranks of top executives who serve on the boards of 142 area corporations, a situation black leaders denounced yesterday as "appalling" and "a slap in the face" to the region's growing minority population.

The survey of major publicly held corporations in Washington, Virginia and Maryland was conducted during the past six months by the Montgomery County chapter of the NAACP.

It found that 94.6 percent of all seats on corporate boards were held by white males, and concluded that was a "contributing factor" to continuing discrimination in the marketplace. The makeup of corporate boards is important, the report noted, because directors are "key decision makers" who wield vast power over the economic and political life of the region.

The NAACP chapter decided to undertake the study because of what it said were increasing reports of discrimination involving qualified and highly educated blacks.

"Many . . . can be called procorporation and probusiness types who dreamed that, because of their education and training, they would escape the rampant discrimination faced by blacks with less education and training," the study stated.

According to census figures, minorities make up 26 percent of the region's population and 70 percent of the District's.

The report singled out 18 firms, including The Washington Post Co., W. Bell & Co., the Hechinger Co., the Rouse Co. and Giant Food, as the most "shocking" examples of "gross underrepresentation."

Each of the companies was identified as having a special link to the black community, either through its customers or, as in the case of The Post, through its long espousal of civil rights; yet each had only token or no minority representation on its board, according to the report.

At the same time, the report named the Rosslyn-based Gannett Co., publisher of USA Today, and Gray & Co., a Washington public relations firm, as "pacesetters" in the appointment of minorities and women to their boards.

With minorities and women holding four of its 18 board seats, Gannett had the best record of appointments, the survey found.

While Gray & Co. has four women on its 14-member board, it has no black man or woman, which the report called "scandalous and offensive."

Half of the region's 10 largest companies and 124 other companies included in the survey had no black directors, while 100 of those companies surveyed had no female directors, according to the report.

Spokesmen for The Washington Post Co., which is headed by a woman, and the Hechinger Co. said black women have recently been added to their boards and other minorities and women will receive consideration for other appointments.

Richard McCauley, a spokesman for the Rouse Co., said his firm may increase its board and intends to give minorities and women consideration. A spokesman for W. Bell said the company has a good record of hiring minorities and the five-member board is made up primarily of family members. Representatives for Giant Food and Washington Gas Light Co. declined to comment.

NAACP officials said they intend to meet with corporate leaders and will ask state legislators to create a blue ribbon commission to study the problem. They also said they will ask U.S. agencies to investigate the situation.