Former Sen. William Proxmire, the Wisconsin Democrat who fought government waste for years with his mocking "Golden Fleece" awards, died Thursday at 90.

Proxmire was known for battling for causes that few colleagues embraced. He won re-election repeatedly without accepting campaign donations and fought for ratification of an anti-genocide treaty, which the Senate approved in 1986, two years before his retirement. The former senator, who suffered from Alzheimer's disease, died at a convalescent home in Sykesville, Md.

"He was a constant profile in courage on countless issues, continually insisting that the Senate live up to its ideals and always willing to wage lonely battles for noble causes," said Sen. Edward Kennedy, D-Mass.

Proxmire's monthly "Golden Fleece" awards, which he began in 1975 to point out what he thought were frivolous expenditures of taxpayers' money, became a Washington tradition.

He was elected to the Senate in 1957 to fill the seat left vacant by the death of Joseph McCarthy, the Republican made infamous for his communist witch hunts.

Proxmire was re-elected in 1958 to his first six-year term and was returned to the same post in 1964, 1970, 1976 and 1982.

Long before the McCain-Feingold campaign finance reform law, Proxmire made a point of accepting no contributions. In 1982 he registered only $145.10 in campaign costs, yet gleaned 64 percent of the vote.

The son of a wealthy physician in Lake Forest, Ill., Proxmire graduated from Yale University and Harvard Business School. He served with military intelligence in World War II and later moved to Wisconsin to begin a career in politics.

After three unsuccessful attempts at winning the governorship, Proxmire won McCarthy's vacant seat.

William Proxmire, 90, a Wisconsin Democrat whose enthusiasm for clean living became as much his U.S. Senate hallmark as his good-governance measures and ``Golden Fleece'' awards, died Thursday at the Copper Ridge care facility in Sykesville, Md. He had Alzheimer's disease.

Mr. Proxmire, who served from 1957 to 1989, was considered one of the most tenacious legislators on Capitol Hill. He built a reputation as a public scold on fiscal matters, even when his focus did not seem to apply to his own state's dairy price supports. He was a political loner in Washington while becoming one of his state's most revered characters.

The senator was a fitness and health advocate - jogging to work, early to bed - and he liked to link his disciplined personal habits with his political image. He was said to reprimand an aide repeatedly for eating doughnuts.

Mr. Proxmire was an independent-minded activist and used his increasingly influential civic pulpit to garner publicity for his causes and, some said, himself.

He was chairman of the Committee on Banking, Housing and Urban Affairs from 1975 to 1981 and became the ranking minority member on the Appropriations Committee.

Those positions gave him more authority to criticize government spending, particularly military expenditures.

In addition, he pushed for consumer protection laws. The most notable was the 1968 Consumer Credit Protection Act, known as the "Truth in Lending Act,'' requiring lenders to disclose interest rates and finance charges owed them by borrowers.

He denounced redlining, a racially discriminatory real estate practice; helped shepherd legislation making it illegal for U.S. companies to bribe foreign governments for business contracts; and played a key role in eliminating funding for a supersonic transport plane.

Over 19 years, he gave more than 3,000 speeches on the Senate floor supporting ratification of an international treaty outlawing genocide before the bill passed in 1986. The measure had spent nearly four decades under consideration.

Mr. Proxmire became a household name for his monthly Golden Fleece awards to highlight ``the biggest or most ridiculous or most ironic example of government waste.'' The ceremony, as such, was a speech on the Senate floor.

Prizes went to studies that used public money to explore why prisoners like to escape from jail and the shapeliness of airplane stewardesses.

He cut a largely solitary figure in Washington. That was an outgrowth of his lone approach to politics by day and his preference to read instead of socialize with his colleagues at night.

Mr. Proxmire attended the Hill School in Pottstown, Pa., where he was voted ``class grind,'' and was a 1938 graduate of Yale University, where he boxed and played football. He served in the Army Counterintelligence Corps during World War II and received two master's degrees, in public administration and business administration, from Harvard University.

He worked briefly for J.P. Morgan & Co. in New York before deciding on a career in politics. He moved to Wisconsin, a state with a history of progressive politicians, such as ``Fighting Bob'' La Follette, one of his idols.

William Proxmire, a political maverick during 32 years in the Senate who crusaded against government waste and irritated presidents and lawmakers from both parties because of his contempt for the mutual back-scratching most politicians engage in, died yesterday in Sykesville, Md., about 40 miles from Washington. He was 90.

He died at the Copper Ridge Nursing Home, said Mindy Brandt, a spokeswoman for the home. Ms. Brandt said she could provide no further details.

Mr. Proxmire had Alzheimer's disease and had been out of the spotlight for more than a decade. He left the Senate in 1989.

A Democrat from Wisconsin, he was chairman of the Banking Committee and was involved in many important legislative battles, most notably successful drives to win Senate approval of a treaty outlawing genocide and rejection of money for a supersonic transport plane.

But he was best known for his Golden Fleece Awards, which he announced in monthly press releases to call attention to what he believed to be frivolous government spending. An award, for instance, went to the National Science Foundation in 1975 for spending $84,000 to learn why people fall in love.

Mr. Proxmire is also remembered for his regimen of daily exercise (in his prime, he jogged nearly 10 miles a day), his spartan diet, his hair transplants and face lift, his refusal to accept campaign donations or reimbursements for travel expenses and his string of not missing roll-call votes, which lasted more than 20 years.

Mr. Proxmire was first elected to the Senate in 1957 to fill the unexpired term of the late Joseph R. McCarthy, the Republican who was censured for reckless attacks on those he accused of being communists or fellow travelers. Although he spent only a few hundred dollars on his campaigns, all of it out of his own pocket, Mr. Proxmire was easily re-elected five times.

His Golden Fleece Award, to gain publicity for his crusade against wasteful spending, became "as much a part of the Senate as quorum calls and filibusters," said Senator Robert C. Byrd of West Virginia, the Democratic leader during part of Mr. Proxmire's career.

Speaking of the National Science Foundation's grant on falling in love, Mr. Proxmire said such a study was better left to "poets and mystics, to Irving Berlin, to thousands of high school and college bull sessions."

Another Golden Fleece Award went to the National Institute for Mental Health, which spent $97,000 to study, among other things, what went on in a Peruvian brothel. The researchers said they made repeated visits in the interests of accuracy.

The Federal Aviation Administration also felt Mr. Proxmire's wrath, for spending $57,800 on a study of the physical measurements of 432 airline stewardesses, paying special attention to the "length of the buttocks" and how their knees were arranged when they were seated. Other Fleece recipients were the Justice Department, for spending $27,000 to determine why prisoners wanted to get out of jail, and the Pentagon, for a $3,000 study to determine if people in the military should carry umbrellas in the rain.

When Mr. Proxmire set his mind to a task, he rarely relented until it was accomplished. For 19 years, he gave a speech on the floor nearly every morning the Senate was in session on behalf of the genocide treaty, more than 3,000 speeches in all. Finally, in 1986, the treaty was approved.

On the Banking Committee, he was tireless in pursuit of laws requiring lenders and credit card companies to disclose true lending rates and legislation enabling consumers to determine their credit ratings. He also pushed for more competition in financial services.

His penny-pinching was the bane not just of defense contractors but also of fellow senators, whose raises and large campaign funds he regularly opposed. Many of his colleagues thought he was a self-centered grandstander.

Generally, he was a liberal, and he was a fierce opponent of the war in Vietnam, but he never toed the party line.