The U.S. Court of Appeals here yesterday eased procedures for federal immigration agents to raid District restaurants and other businesses for illegal aliens, overturning more restrictive standards that had been imposed by a lower court judge since 1978.

The three-judge panel, in a unanimous decision, said U.S. Drist Court Judge Louis F. Oberdorfer erred when he held that Immigration and Naturalization Service agents must meet more rigid standards required in criminal investigations, including naming or describing each alien, when they sought court approval to search businesses.

"Since an illegal alien is essentially a fugitive outside the law, it is unlikely that his vital statistics will be on file anywhere in the United States," said the opinion by appeals Judge Carl McGowan yesterday.

Search warrants are sought in those cases where owners refuse voluntarily to allow law enforcement officers to enter their businesses.

Oberdorfer had ruled in a case involving an INS search for illegal aliens employed at Blackie's House of Beef, 22nd and M streets NW, in November 1978, in which 14 persons were arrested. The restaurant, which had refused to give INS permission to search the place, sued and Oberdorfer ruled the raid violated Blackie's constitutional right against unreasonable searches.

As a result, INS officials in the District had confined themselves to searching only businesses that gave their consent, said senior INS official Glenn Bertness yesterday. He said although he had not yet seen the ruling, he would expect INS to resume seeking warrants to search businesses suspected of employing illegal aliens, a practice that the agency has continued to follow elsewhere in the country.

The appeals court also rejected Oberdorfer's finding that the magistrate who issued the warrant against Blackie's did not consider adequately the raid's effect on Blackie's did not consider adequately the raid's effect on Blackie's patrons and other employes. "This warrant on the whole was reasonable and reflects a balancing of public and private interest," the court said.