Congress intended to preserve the power of the states to regulate pension plans, including those negotiated in collective bargaining, the Supreme Court ruled yesterday.

The 5 to 2 ruling reversed the 8th Circuit U.S. Court of Appeals, which in October invalidated Minnesota's Private Pension Benefit Protection Act in a case involving White Motor Corp.

The case began in 1963, when White Motor bought two plants that manufactured farm equipment. The plants' workers had a pension plan established under contracts with the United Automobile, Aerospace and Agricultural Implement Workers of America.

Under an agreement reached with the union in 1971, pensions were to be payable only from a fund established under the agreement, partially on a deferred basis. The company had the right to terminate the plan, but guaranteed to pay benefits amounting to $7 million in excess of assets.

The company closed one of the plants in 1972 and tried to terminate the pension plan, although almost 1,000 employes were entitled to retirement benefits.

In April 1974, the state enacted the pension law, which imposed "a pension funding charge" directly against any employer who shut down a plant or a pension plan. The state certified that the pension funding charge owed by White Motor was not $7 million but $19.15 million.

The company sued, alleging that the state law conflicted with the National Labor Relations Act (NLRA) because it interfered with White Motor's right to free collective bargaining and invalidated the labor contracts it had with the UAW.

A federal judge ruled for the state. The appeals court reversed, but was overruled by the Supreme Court.

In the opinion for the court, Justice Byron R. White said that in both the Welfare and Pension Plans Disclosure Act of 1958 and the Employe Retirement Income Security Act (ERISA), which took effect Jan. 1, 1975, Congress "clearly anticipated a broad regulatory role for the states."

The Minnesota law "seeks to protect the accrued benefits of workers in the event of plan termination and to insure that the assets and prospective income of the plan are sufficient to guarantee the benefits promised - exactly the kinds of problems . . . Congress hoped that the states would solve," Justice White wrote.

In separate dissents, Justice Potter Stewart and Lewis F. Powell Jr., each joined by Chief Justice Warren E. Burger, said that the majority relied on evidence as to what Congress had not done in the 1958 law. This evidence was insufficient to justify overriding national labor policy barring interference by the states with collectively bargained terms of pension plans, the dissenters said.

Justics William J. Brennan Jr. and Harry F. Blackmun, who were ill when the case was considered, did not participate.

The court took other actions. Fraud Judgement

The court let stand a $1 million fraud judgement obtained by First Virginia Bankshares against Walter E. Heller & Co., a Chicago financial institution, and two top executives of Benson Investment Co., an Alabama-based consumer finance firm operating in the Southeast.

First Virginia acquired Benson Investment in 1973. The Heller firm was the largest - and only - secured creditor of Benson Investment.

First Virginia, claiming it had been defrauded, sued the Heller firm, and also George J. Benson, chairman and largest stockholder, and Alan Benson, chief executive officer of the consumer finance firm.

A jury awarded the $1 million. The 5th Circuit U.S. Court of Appeals affirmed. Only the Heller firm sought Supreme Court review. Tax Rebellion

The court let stand the convictions of Ronald L. and Della M. Foster, a Los Angeles-area couple who failed to file federal income tax returns for the years 1969 and 1972. They acted as members of a "Tax Rebellion Group," which contends that government monetary and fiscal policies violate constitutional rights. In 1972, the Fosters' combined income was $19,500.