The Equal Employment Opportunity Commission, in an important shift in policy, served notice yesterday that it is moving away from broad complaints against large companies and entire industries in favor of more tightly focused cases involving specific persons.

Chairman Clarence Thomas said the new policy will return the EEOC to its proper function as a law enforcement agency: a person complains, his complaint is acted on. But critics said that, with the shift, the agency is giving up leverage in the job market as a whole.

In the past, the agency has brought a number of celebrated broader actions against such targets as AT&T; the steel industry; Sears, Roebuck and General Electric. In these cases it has alleged general patterns of discrimination and pressed for relief for entire classes of employes.

"We absolutely want good enforcement and vigorous remedies for individuals," Anne Ladky, executive director of Women Employed, a Chicago advocacy group that monitors the EEOC, said yesterday. "At the same time, we understand that discrimination is by its nature systemic and there is a need for class action to make progress. If the government only pursues discrimination in individual cases it will not make progress in eliminating discrimination overall."

Commission members said the agency will take more cases to court, however, and that this will compensate for the shift away from broader complaints.

"We are going to go all-out for anybody that was wronged," Thomas said. "We'll seek remedies for individuals by litigating cases where there is a finding of discrimination. That is what this agency should be doing . . . . This is a significantly tougher stand for people who have been hurt by discrimination.

"No platitudes, no vision," Thomas added. "We are going to right the wrong. No goals or timetables, either. Just hire the person you discriminated against tomorrow . . . if necessary, fire the person you hired when you should have hired the person you discriminated against."

Thomas said the agency may still on occasion bring broader actions against employers and seek broad reforms. But in cases that do not involve identifiable victims of discrimination, he said, no compensation will be sought -- just procedural changes.

Only persons who can prove that they have been subject to discrimination will be "made whole for any loss of earnings" and given back lost jobs, the agency said yesterday.

There have been disputes for years about EEOC procedures -- whether the agency should emphasize broad or narrow actions; whether it should lean toward litigation or conciliation.

Commission member William A. Webb said the new emphasis on litigation will mean larger settlements for victims of discrimination. He also said that, by going to court instead of frequently settling cases outside, the agency will pose a greater threat to employers who illegally discriminate.

"You could not count on us to sue you if you were caught violating the law," said commissioner Fred W. Alvarez at a news conference to announce the policy adopted by the panel, all five of whose members were appointed by President Reagan. "We thought we should adopt a policy of certainty in this area."

Webb said the commission felt especially that compensation should go only to proven victims of discrimination, not to entire classes.

"When somebody tells me they ought to get something because they're Irish and saw signs in Boston that said 'Irish Need Not Apply' when they were in grade school; or that they are Italian and their grandfather could not get hired in New York; or that their ancestors were in slavery, I say, so what," he said. "This agency is not in the business of windfall legislation. We want to make people whole who have been damaged by discrimination."

Critics said the new policy shows that the Reagan administration is weakening government's role as an aggressive enforcer of civil rights.

One civil rights lawyer familiar with the agency said the new policy will ensure that the EEOC "never gets quality litigation for civil rights cases, because you cannot find quality cases in individual complaints . . . . They are helping a random person here and there."

"The EEOC has been a tremendous disappointment in the last four years," said Ladky. " . . . What they're saying now is enforcement won't be vigorous."