The American Federation of State, County and Municipal Employees announced yesterday that it had reached a settlement in its landmark pay-equity case against the state of Washington that provides for distribution of $482 million to 34,000 state employes.

At issue was the controversial concept of "comparable worth," a novel legal theory that goes a step beyond the principle of equal pay for equal work by seeking equal pay for jobs of comparable worth.

Opponents of comparable worth, including President Reagan and many business leaders, are expected to view the out-of-court settlement as a victory because it leaves standing an appeals court ruling of last September that rejected the concept.

The pact also does not provide for back pay, which had been estimated at nearly $1 billion.

Under the agreement, men and women in the specified classifications will receive $46.5 million during the first 15 months and $10 million on July 1 every year thereafter through 1992 to correct sex-based inequities in the state's wage scales. The employes also will receive regular pay raises.

The settlement must be reviewed by the Washington legislature and U.S. District Court Judge Jack E. Tanner in Tacoma, who ruled in 1983 that the state had violated provisions of the federal Civil Rights Act that forbid job discrimination.

The Washington case long has been viewed by unions and feminist groups as the lead case in their legal battle to establish the concept of comparable worth, which Reagan has condemned as "a cockamamie idea . . . that would destroy the basis of free enterprise."

The case began in 1981 when a state-commissioned study found that state workers in male-dominated jobs were being paid 20 percent more than workers in female-dominated jobs. Among other provisions, the study recommended that laundry workers be paid as much as truck drivers, and librarians twice as much as carpenters.

In 1983, Tanner ordered a salary increase and back pay for more than 15,000 state workers in female-dominated jobs. But last September, the ruling was overturned by the 9th U.S. Circuit Court of Appeals in San Francisco, which found that federal law does not require the state to eliminate inequalities for which it was not responsible.

Before the appeals court ruling, the Washington legislature appointed a task force to negotiate a settlement with the union and appropriated a fund of $41.6 million to finance the settlement. Yesterday's agreement, which is the result of those negotiations, will require additional appropriations by the legislature.