Harrison A. "Pete" Williams Jr., 81, a liberal Democratic senator from New Jersey whose service from 1959 to 1982 brought him the nickname "senator for life," but who resigned rather than face expulsion for his role in the Abscam bribery scandal, died Nov. 17 at a hospital in Denville, N.J. He had cancer and heart ailments.

Sen. Williams, a lawyer who from 1953 to 1957 was a U.S. representative from New Jersey, built a strong record on workers' rights and safety legislation. He was a force in the passage of legislation creating the Occupational Safety and Health Administration and the Employee Retirement Income Security Act law that set federal standards for pension benefits. His chairmanships included the Committee on Labor and Human Resources and the Special Committee on Aging, as well as a banking securities subcommittee.

To many, those accomplishments were overshadowed by the elaborate FBI undercover operation known as Abscam that began in 1978. Short for Arab scam, it involved FBI agents and informants posing as Arabs seeking political favors.

Sen. Williams was caught on camera agreeing to use his official capacity to advance business interests in which he had a stake. Abscam led to the conviction of six congressmen in addition to Sen. Williams.

He was indicted in 1980 and convicted the next year by a New York federal court on nine counts of bribery and conspiracy. He fought expulsion efforts in the Senate but was unable to muster significant support among his colleagues.

Sen. Williams, who maintained his innocence and said he was entrapped, was sentenced to three years in prison. He served most of that time at a federal correctional facility in Allenwood, Pa., and then entered a halfway house in Newark. He was the first senator to serve jail time in about 80 years.

At his death, Sen. Williams, a resident of Bedminster, N.J., served on the board of directors of a drug treatment facility in Newark. One of the first senators to publicly acknowledge an addiction to alcohol, he spent recent years training substance abusers for post-treatment jobs and advising treatment programs on how to obtain state and federal funding.

He made an unsuccessful attempt last year to persuade then-President Clinton to give him a presidential pardon.

Harrison Arlington Williams Jr., a native of Plainfield, N.J., was the son of a prominent businessman.

He once told a reporter he got his nickname Pete from a "salty grandfather who was a stagecoach driver, a farmer and an Adirondacks mountaineer." The grandfather was with his pal Pete when he got word via telegram of his grandson's birth. "My grandfather exploded: 'That name's too much -- let's wire back, 'How's Pete?' "

He was a 1941 economics graduate of Oberlin College and attended Georgetown University's foreign service school in the early 1940s while working as a Washington Post copy boy. He was a Navy veteran of World War II and a 1948 graduate of Columbia University law school.

He practiced law in New Hampshire and New Jersey, and made unsuccessful bids in the early 1950s for the New Jersey state house and the Plainfield City Council.

When liberal Republican Rep. Clifford P. Case resigned in 1952 to pursue a Senate seat, the young lawyer and budding politico won Case's old New Jersey House spot against all odds. He persuaded voters in the heavily Republican district that he would follow Case's policies and support President Dwight D. Eisenhower.

He became an unusually outspoken young congressman, and his legislative efforts included submitting a bill on immigration policy that he hoped would "rid us of the legalized snobbery of the national origins quota."

He served two terms in the U.S. House, until he lost his reelection bid in a statewide Republican landslide.

He reactived his political career in 1957 by campaigning exhaustively for the reelection of New Jersey Gov. Robert B. Meyner (D). Meyner, in turn, promoted former representative Williams as the Democratic Party's best hope to win the 1958 Senate race. Sen. Williams ultimately gave Garden State Democrats their first such seat in three decades.

In the Senate, he became a stalwart of liberal causes, including Social Security and health benefits, conservation, urban renewal, labor issues, migrant-workers' rights and civil rights.

His stature was greatly diminished by the Abscam controversy, in which Sen. Williams was convicted of nine counts of bribery and conspiracy. He was found to have accepted a hidden 18 percent share of a Virginia titanium mine financed by the faux Arab investors. In return, the senator promised to use his contacts to ensure that the mine received government contracts.

In addition to the three-year prison term, Sen. Williams was ordered to pay $50,000 in fines.

Despite a rigorous Senate defense by Sen. Daniel K. Inouye (D-Hawaii), Sen. Williams was unable to overcome a unanimous recommendation for expulsion by the Senate ethics committee. On Aug. 24, 1981, the ethics committee found that "Senator Williams's conduct was ethically repugnant to the point of warranting his expulsion from the United States Senate."

He resigned on March 11, 1982, telling his colleagues from the Senate chamber: "It is not only Pete Williams that stands accused or indicted. It is all of us, the entire Senate, that stands accused and intimidated by another branch of government. . . . The chairman of the Select Committee on Ethics [then-Sen. Malcolm Wallop (R-Wyo)] . . . shelters the FBI and its malcontents from criticism in his prosecution of me. In so doing, I believe he makes the next Abscam easier and more legitimate."

He added that "time, history and Almighty God will vindicate me and the principles for which I have fought here in the Senate."

Five congressmen resigned from office or were defeated for reelection. The sixth, Michael J. "Ozzie" Myers (D-Pa.), was expelled from the House.

Sen. Williams's marriage to Nancy McGlone Williams ended in divorce.

Survivors include his wife, Jeanette Smith Williams, and four children from his first marriage.

Harrison A. Williams was instrumental in passage of workers' rights and safety legislation.