The Supreme Court yesterday significantly expanded federal power over state and local authorities by making them vulnerable to a broad new variety of damage suits for federal rights violations.

State and local officials already can be sued for damages for major denials of civil rights. Yesterday, the court ruled, 6 to 3, that they also can be sued for denial of any federal benefit provided through them.

The court provided an important potential incentive for such suits by ruling that a plaintiff who prevails can collect legal fees from the governments.

The ruling gives victims of alleged violations a powerful new remedy. But in the view of dissenters, it is also a dangerous breach of the principles of federalism. The ruling is "a major new intrusion into state sovereignty" and could loose a flood of money damage claims against state and local governments, wrote Justice Lewis F. Powell Jr., with Chief Justice Warren E. Burger and William H. Rehnquist.

The ruling in Maine vs. Thiboutot originated with a suit against Maine's commissioner of human resources, who was accused of unfairly denying welfare benefits to Lionel and Joline Thiboutot and their eight children.

Because the welfare program is federally financed, the Thiboutots' class-action suit demanded money under, a provision of the Civil Rights Act of 1871.

The state argued that the act, passed to implement the new rights given blacks after the Civil War, allowed money damages only for deprivation of rights guaranteed by the Constitution. Welfare, they said, is guaranteed not by the Constitution, but by federal law.

But Justice William J. Brennan Jr., writing for the majority, said that the 1871 act also protects benefits conferred by welfare laws.

That by itself was not new; the court has gradually expanded the coverage of the civil rights law. But yesterday, the court extended coverage to "any law" enacted by Congress.

The dissenters said that at least 30 laws -- all involving federal cooperation with state and local governments -- were brought into the fold by the decision. The laws range from the Federal Insecticide, Fungicide and Rodenticide Act to statues protecting or financing historic sites, fish and wildlife, scenic areas, highways, water projects, food stamps and education.

Some of those laws contain their own remedies for violations, but many do not, and few are as powerful as the remedies under civil rights law.

"In practical effect," the dissenters said, the decision "means that state and local governments, officers, and employes now may face liability whenever a person believes he has been injured by the administration of any federal-state cooperative program, whether or not that program is related to equal or civil rights."

The dispute revolves around the purpose of the act and the specific provision (Title 1983) that allows damages for deprivation of rights by governments or anyone acting under "color" of law.

The provision initially was used to allow federal intervention when southern authorities rufused to protect blacks against rights infringements. Recently, activists have used it for a remedy against unprovoked shootings by police, illegal wiretaps, firings based on religion and other offenses.

In 1874, Congress revised the provision to say that it protected not only constitutional rights but rights secured by "the Constitution and laws."

Brennan wrote that "'and laws means what it says. . . . Congress attached no modifiers to the phrase." It thus covers laws -- such as welfare -- enacted by Congress.

The dissenters argued that the history of the provision, directed at oppression of blacks and abridgement of fundamental rights, limited its application to violations conventionally associated with civil rights.

The civil rights provision also allows the award of majority held yesterday that states have to pay if the plaintiff wins the suit.

Because the federal government does not have to pay attorney's fees when it loses such suits, the ruling is likely to encourage lawyers to sue the local authorities instead of the federal government, which often can also be sued for the same allegations.