The Justice Department said yesterday that allegations of wrongdoing by the General Services Administration in the awarding of long-distance telephone equipment contracts concern gratuities.

The allegations center on whether "someone did a favor for someone to achieve favorable treatment on a contract," Justice spokesman John Russell said. He declined to elaborate, saying, "we haven't seen any papers" yet. The GSA's inspector general has asked the Justice Department's Public Integrity Section for assistance in the probe.

Also yesterday, a federal administrative judge moved to block potential destruction of documents pertaining to an investigation of the disputed contracts worth $55 million that were awarded by the General Services Administration in October.

The judge's action to protect the documents was in response to a motion by American Telephone & Telegraph Co., which said that there was a "special risk that documents may be destroyed or secreted" as a result of the criminal investigation under way into the contracts.

The contracts in question were for sophisticated switching equipment to upgrade the federal government's long-distance telephone system. The equipment is intended to hold the system together until the phase-in of an entirely new system, known as FTS-2000, which will be the largest civilian contract ever awarded by the federal government.

Sources familiar with the investigation say that several GSA officials involved in the switch contracts have declined to give sworn testimony verbally or in writing. The GSA said yesterday that the request for help to the Justice Department had been made in part because Justice has the legal power to compel testimony.

A third party is also investigating the case -- the Senate Governmental Affairs Committee, chaired by Sen. John Glenn (D-Ohio). "We are actively reviewing the situation independently," committee counsel Stephen Ryan said yesterday.

"Sen. Glenn is always concerned that the government get the best possible deal for the dollar and all of the competitors in government procurement be treated equally," Ryan said.

Under contracts awarded in October, five of 12 switching centers went to AT&T. AT&T later filed a formal protest with the Board of Contract Appeals, an independent body that adjudicates contract disputes, saying that GSA had unfairly evaluated its proposal by using different standards than those applied to its competitors.

Proceedings for resolving AT&T's dispute were under way when GSA requested last month that they be suspended because its inspector general had received allegations of wrongdoing and had launched a probe of his own. So far the allegations have not been proven. The board agreed to a two-week suspension.

AT&T has complained loudly since the suspension began that it has been kept in the dark as to the reasons for it.

It has also strongly hinted in court papers that the suspension may be a ruse for delaying resolution of its protest.

Earlier this week, Yesterday, AT&T asked for an order barring destruction of papers.

Judge Vincent A. LaBella of the board granted it. He turned down a request from AT&T for an oral hearing on the suspension and granted a motion by GSA to extend the suspension of AT&T's case, which was supposed to have ended yesterday, for five more days. until midnight Dec. 8.