Washington Gas Light Co.'s pledge to the NAACP to do more business with minority contractors has a certain public relations effect to it.

Ostensibly, local minority firms will benefit from the agreement with WGL, but once you get past the hoopla of last week's press conference at which the agreement was announced, the immediate benefits are likely to accrue to the parties who signed it.

By getting the commitment from WGL and other utilities, the NAACP can boast that its national Fair-Share program is having as much success as the Rev. Jesse Jackson's Operation PUSH campaign to extract agreements from big business.

The more controversial program spearheaded by Jackson uses the threat of boycotts to pressure big companies into granting franchises and distributorships to minorities. In the case of the NAACP, which adopted a set of "fair-share principles" last year, the initial thrust is to get utilities to agree to review and broaden business and employment opportunities for minority firms and professionals.

A consultant to the NAACP recently admitted being concerned that the organization isn't getting enough exposure for the Fair-Share program, implying that it won't work without the glare of publicity.

WGL, meanwhile, despite positive statements in the past about its policies affecting minorities, has failed to convince some company employes of its sincerity. Although their claims may have no basis in fact, a group of minority employes at WGL has filed suit in U.S. District Court, accusing the company of discrimination in its hiring and promotion policies.

By endorsing the NAACP's "Declaration of Fair-Share Principles," which were adopted by the American Gas Association last year, Washington Gas is in a strong position to rebut negative claims about its hiring and promotion practices. Indeed, the company emphasizes in its support of the fair-share principles that it has "encouraged and developed policies and practices to facilitate the movement of blacks and other minorities into the mainstream of the business community."

The agreement is more of an affirmation of WGL policies, a spokesman confirmed later.

In support of the principles, WGL pledges to administer an effective minority purchasing program, provide opportunities to increase the dollar value of purchases from minority contractors, consider blacks and other minorities for election to its board, and review and evaluate the potential within the company for appointment of blacks to senior management positions.

At least 10 other gas companies have given similar commitments to the NAACP. And locally, Potomac Electric Power Co. played a leading role last year in helping to draft the declaration of fair-share principles, which was adopted by the Edison Electric Institute.

To be sure, some utilities can't claim to have exemplary records when it comes to minority purchasing and hiring programs. The same can be said of other types of companies, however. The NAACP must have had a unique reason, therefore, for singling out the utilities industry for carrying out its fair-share program.

The explanation provided by an NAACP consultant working on the program wasn't very convincing. Consumers have little choice but to use the services of utilities, and those companies have what amounts to a captive market, he explained.

Perhaps. But one probably can make a good case that many utilities are light years ahead of other industries or individual companies in providing business and employment opportunities for minorities. A study of minority representation on the boards and in senior management of Fortune 500 companies, for example, might be of more use to the NAACP in its effort to bring blacks into the mainstream of American business.

In the meantime, Pepco and WGL have managed to do that to some degree without having to agree to a declaration of fair-share principles.

For example, the Maryland-D.C. Minority Suppliers Development Council cited Pepco as its "corporate member of the year" in 1982 for the company's program to provide more business to minority firms. Besides having two minorities on its board, Pepco has one of the better records among local companies in appointing blacks to management positions. In fact, 13 percent of its management employes are black.

WGL, which also has a black director on its board, identifies 14 percent of its supervisory staff and 34 percent of the total work force as minorities.

While there may be room for improvement among local utilities, few publicly held companies here have matched their examples.