President Reagan has decided to request another $76 million this year for the special nutrition program for pregnant women, infants and children for this year, bringing the total to the full $1.5 billion that Congress approved last year, the Office of Management and Budget announced yesterday.

Last year Congress appropriated $1.5 billion for the WIC program, enough to feed about 3.08 million people. But it made the release of the last $246 million contingent on a request by the president. Early this year, instead of seeking the full amount, the president requested $76 million less and the Agriculture Department began allocating the WIC funds to the states on the basis of the smaller amount.

That prompted a lawsuit by the Food Research and Action Center (FRAC), five states and four members of the Congress to force the administration to spend the entire amount.

In addition, the Senate voted, 97 to 0, last month for a budget amendment sponsored by Sen. Dennis DeConcini (D-Ariz.) and others, expressing the sense of the Senate that the full amount should be spent.

OMB spokesman Edwin L. Dale Jr. said the request for the $76 million carried out the agreement between the administration and Senate Republicans that WIC funds should grow each year to maintain the current level of services, starting from a base of $1.5 billion in 1985.

Michael Lemov, director of FRAC, said, "This is a victory for maternal and child nutrition advocates and an admission by OMB that they have acted unlawfully in withholding funds." But he said the lawsuit might continue because certain issues were unresolved, such as whether the plaintiffs were entitled to recover the costs of the suit and how to treat additional outlays that some states may have made when the federal funds were reduced.