A Virginia real estate firm asked the U.S. Supreme Court yesterday to limit the rights of fair housing groups to bring racial discrimination lawsuits.

The dispute, which has drawn national attention from the real estate industry and civil rights organizations, centers on the use by fair housing groups of antibias investigators, known as testers. A common technique is to send white and black testers to a real estate agency in an attempt to determine whether the firm will sell or rent housing to whites but deny housing to blacks.

The legitimacy of this tactic was challenged in arguments before the Supreme Court yesterday by Everette G. Allen Jr., a lawyer for a suburban Richmond real estate company that was found guilty last year of engaging in racial discrimination. Allen objected to the use of testers by a Richmond-area equal housing group. "They were not in any way bona fide apartment seekers," he said.

The court proceedings stem from a decision last year by the 4th U.S. Circuit Court of Appeals in Richmond, which granted testers the right to seek court action to stop housing discrimination even though they do not claim they themselves were harmed by the alleged bias. Normally, persons are granted "standing," the legal right to assert their claims in court, only if they allege they were injured or damaged.

The appeals court's decision disturbed the real estate industry. The 600,000-member National Association of Realtors charged, in a brief filed with the Supreme Court, that the Richmond appeals ruling had created an "instrument of legal harassment" that may be used to coerce real estate firms into agreeing to unwarranted settlements to resolve bias claims.

Civil rights organizations, worried about prospects of an adverse high court decision, have urged the jurists to consider setting aside the issue without ruling on it. They argue that a consent order issued by a lower court in Richmond in a parallel lawsuit involving the same real estate company, Havens Realty Corp., may have rendered the controversy moot.

The Justice Department also has urged the Supreme Court to consider dismissing the lawsuit on grounds it may be moot. At the same time, however, the government contends that the 1968 Fair Housing Act, which bars racial bias in housing, should be interpreted as extending to the use of testers.