A federal judge here accused the Federal Aviation Administration yesterday of trying to make an "open-ended attempt to circumvent" his earlier order blocking the transfer of a small group of FAA employes to its Atlantic City facility.

Using a loophole in a July 25 order by U.S. District Court Judge Harold H. Greene, the FAA had decided that while it could not order its people to transfer now, it was not prohibited from transferring the workers' job functions to the New Jersey office and had already shipped 90 to 95 percent of their work papers there.

But yesterday, in a clarification of his earlier order, Greene ordered the FAA to immediately return the workers' job functions back to Washington, as well as any employe who does not wish to make the move.

The estimated 35 workers in the FAA's airport planning and aircraft safety and noise abatement divisions had been ordered to report to Atlantic City by tommorrow. But some of the workers, most of whom are in their late 40s or older, have claimed that they were singled out for the move because they are older employes and thus are likelier to retire rather than move.

In his earlier order, Greene said that the FAA has not demonstrated that its (transfer) decision was based on reasonable factors other than age." In his ruling yesterday, the judge reiterated that "there is a substantial likelihood that (the workers) will prevail" when the case goes to trial. If the workers win, they would be entitled to damages under the provisions of the Age Discrimination in Employment Act.

The FAA said it had no immediate comment on the judge's new ruling, but the workers' lawyer, Harvey M. Katz, said that Green "gave us everything we wanted. I don't see anyway (the FAA) can get around this one."

In his first order, Green said that the FAA could allow any employe to go ahead and move who wanted to if the worker had already made plans to move. The FAA, however, interpreted that provision as permission to urge its workers to go ahead and make the shift to Atlantic City in spite of the judge's order.

The agency sent letters to supervisory personnel saying that "you can understand that your reporting as scheduled (on Sunday) is considered vital." Nonsupervisory employes got letters saying, "As you can appreciate, we hope that all persons associated with the transfer of functions proceed as scheduled to Atlantic City in order that we may get on with our mission."

Greene, in the new ruling, said the FAA is "see-ing to convert an exception provided for the benefit of employes who had previously made concrete plans to move, into an open-ended attempt to circumvent the court's order."

Under his new order, Greene said the FAA could only allow employes to go to Atlantic City if they had made arrangements to go before July 25 and now still wish to go.

Until yesterday's order, the FAA said that seven workers had decided to go to Atlantic City and five had opted for retirement. Stephen A. Cannistra, 64 a $40,000-a-year, 20-year-FAA employe and one of four men who filed suit to block the transfers, said that another 20 to 24 are still fighting the transfer.

It was not immediately known how many of the dozen workers who had chosen to move or retire might now change their plans. Cannistra said that those going to Atlantic City have and that only one had bought a house so far.

Cannistra and others affected by the proposed move said they feared that with their job functions and papers shipped to Atlantic City they would have trouble doing their work properly and also would be forced to make frequent trips to New Jersey to look at their files.