A General Services Administration official who allegedly received over $600,000 in kickbacks and then urged a contractor to lie before a grand jury yesterday received the stiffest sentence yet in the GSA corruption scandal.

U.S. District Court Judge Oliver Gasch sentenced Robert M. Beacham, who had charge of federal buildings near the State Department for GSA, to six years in jail and a fine of $35,000.

As part of the evidence against Beacham, Assistant U.S. Attorney William S. Block introduced transcripts of conversations monitoried by the FBI between Beacham and GSA contractor Eugene C. Ebel.

Ebel had agreed to be wired by the FBI for sound and a transcript shows that Beacham told him:

"No you can't say that, man. "You'll put us deeper."

Beacham supposedly had agreed to cooperate with Block in continuing GSA investigations and tell the truth. But he told Ebel," . . . He thinks I tell the truth, but I don't."

Beacham was indicted this year for obstruction of justic and perjury as well as bribery, fraud and submitting false claims to the government.

Like others GSA officials involved in the scandal, Beacham awarded contracts to perform little or no painting and alteration work in return for kickbacks from contractors.

He warded $3.5 million in contracts and got $614,000 in kickbacks, according to prosecutor Block.

Besides $450,000 in cash, Block said, Beacham received from one or more contractors a sailboat, a boat dock, much of the price of a luxury car, jewelry, clothing, furniture, interior painting and wallpapering, drapes, contributions to a social club, darkroom equipment, corporate stock and trips to Las Vegas, Colorado and the Bahamas.

In March, Beacham pleaded guilty to receiving more than $75,000 in kickbacks. His lawyer, Plato Cacheris, told Gasch yesterday that the higher kickback figure of $614,000 has not been "verified."

Cacheris yesterday noted that Beacham had already pleaded guilty to an amount that was "sufficient to show a crime."

"Out of a misguided sense of loyalty, he withheld information. He tried to protect a friend and he was wrong," Cacheris said. He described Beacham, who lives in Gaithersburg, as a "community spirited" individual.

"I'm extremely sorry for what I've done," Beacham told the judge. "When I joined the government I was an honest and sincere person."

He cited pressure from superiors to spend all of GSA's budget by the end of the year, explaining that the agency had a nonchalant attitude about money.

"After a while -- I was with the government 15 years -- money became sort of useless, zero," he said.

Block, noting that Beacham had tears in his eyes, said Beacham also had shed tears when he promised Block he would tell the truth and cooperate in the investigation.

"He has lied to the U.S. attorney's office and to his own attorney," he said. "Most important, he has lied to a federal grand jury."

Without comment, Gasch imposed sentence. Beacham stared at the judge until Cacheris tapped him on the shoulder to suggest he sit down.

The monitored conversations show Beacham complained in January that he expected to receive a jail sentence of six months.

"I'm gonna do six f----- months . . . Six f----- months," he told contractor Ebel.

So far, 91 individuals and corporations have been indicted in the GSA scandal, and 83 have pleaded guilty or been convicted. Two persons have been acquitted.

Fifty-three of the cases were brought by the U.S. attorney's office in Baltimore, 31 by the U.S. attorney's office in Washington and seven by a Justice Department tast force on GSA corruption.