Assistant Attorney General William F. Baxter, acknowledging a mix-up in signals with the Federal Trade Commission, said yesterday that he would give the FTC more time to study possible antitrust problems with the oil drilling leases the Interior Department awarded last week.

Even though the FTC is still investigating about 80 percent of the bids made for leases off the Alaskan coast, Baxter told the Interior Department last week to issue the leases because the Justice Department did not believe that they posed any anticompetitive problems.

In a telephone interview yesterday, he said he gave the Interior Department clearance for the leases -- worth $2 billion to the U.S. Treasury -- after a phone talk with FTC Chairman James C. Miller.

The call was made to see if the FTC had completed its investigation of the bids made by British Petroleum, Standard Oil (Ohio), Atlantic Richfield Co., Shell Oil Co. and Exxon Corp. -- the dominant companies in the crude oil market on the West Coast.

The FTC had concluded that while the bids by the other oil companies did not pose any antitrust problems, it needed more time to study the bids by these five to see if they would reduce competition.

Under law, Interior cannot grant the leases until it has sought the advice of the Justice Department -- which in turn must consult with the FTC -- to see if the awarding of the leases would be anticompetitive. But the law does not require Interior to follow their advice.

Although Baxter would not disclose exactly what was said in his conversation with Miller, he said, "I understood him to say that they were finished with the study" and that therefore Justice would be able to give the go-ahead to the leases.

"Now it is fairly clear that he (Miller) didn't mean to say that," Baxter said.

Baxter said that while he would not tell Interior to withdraw its awards, he was still open to listening to any of the FTC's findings.

"If the FTC should really come up with a problem that we didn't foresee, it's really not too late to do something . . . These mineral deposits are not going to go away," he said.