A substantial discrepancy in John Tower's descriptions of his business dealings with a British aircraft and weapons manufacturer has been found by the Senate panel weighing his nomination as defense secretary, it was reported Saturday.

Tower testified last week that he had represented British Aerospace Inc. only on civil aviation matters, not as a consultant on military systems.But, in a divorce deposition, taken in June 1987, Tower stated that he had given the company advice on "selling certain systems to the Defense Department," the Los Angeles Times said.

In the deposition, Tower reportedly said he represented the firm on a range of military programs and was paid $8,000 a month. Records show that the payments continued from June 1986 until December 1988. Also, Tower apparently served on the board of directors of the company, the U.S. subsidiary of British Aerospace PLC.

The discrepancy, unidentified sources told the Times, has prompted concerns about the veracity and completeness of Tower's testimony before the Senate Armed Services Committee.

And it raised the question of whether Tower should have registered as a lobbyist for foreign interests under the Foreign Agents Registration Act, the sources said.

Tower's relationships with arms makers are central to reservations expressed by some senators about his nomination. Tower has made at least $760,000 in 21/2 years of employment in weapons firms.

As a result of the discrepancy, Tower may be recalled to testify under oath about his work for the firm.

A lengthy FBI investigation into his business dealings and his personal behavior has stalled a vote by the committee on his confirmation. The FBI is looking into new charges about Tower's alleged drinking, womanizing and receipt of campaign contributions and has said it cannot complete the inquiry for another 10 days.

The FBI is trying to determine whether Tower, who left the Senate in 1985 after 24 years, received illegal corporate campaign contributions from a military electronics firm that later became part of Unisys Corp.

The sworn deposition about Tower's business dealings was never filed in court because Tower chose not to contest the divorce from his second wife, Lilla Burt Cummings. But the document was obtained by the FBI as part of its background investigation of the nominee and is included in the committee's file on Tower.

In the deposition, Tower said he advised British Aerospace on its chances of selling its training jets, fighter planes and missile systems to the Pentagon.

Among the British Aerospace products Tower tried to sell to U.S. military officials were the Tornado fighter, the Hawk trainer, the Rapier anti-aircraft missile and the Seawolf short-range air defense system for ships, according the Times review of the deposition.

He said in the document that he had been valuable to the firm because he was "plugged in in this town" and "knows the defense business pretty well."

Secretary Garn?

Sen. Jake Garn, R-Utah, is scoffing at rumors that he could be next in line as defense secretary if John Tower's nomination fails.

"I don't know where that comes from," Garn said Thursday. "I expect Sen. Tower will be confirmed. I've been in the White House on three occasions in just the last week talking about the savings and loan crisis. Certainly no one down there has mentioned it to me, so I don't know where the rumor is coming from."