WASHINGTON--President Reagan was aware that money was being raised to provide arms for the Nicaragua rebels, Sen. Daniel Inouye (D-Hawaii) said yesterday, but Reagan insisted his knowledge of private aid efforts was limited to a television campaign to garner support for the contras.

Meanwhile, the former ambassador to Costa Rica said Assistant Secretary of State Elliott Abrams '69 and other senior officials ordered him to assist Nicaraguan rebels, according to a report published in yesterday's New York Times.

Lewis A. Tambs resigned as U.S. ambassador to Costa Rica in January amid reports that he and his staff had improperly assisted the contras.

Inouye, the chairman of the Senate committee investigating the Iran-contra affair, said the President "knew much more" than the White House has admitted, but Reagan said in an impromptu encounter with reporters yesterday he had "no detailed information" about the private network.

Inouye heads the Senate committee that, alongwith a companion House committee, will open publichearings today into the secret sale of U.S. armsto Iran and diversion of payments to Nicaraguanrebels. The complicated case has turned into theworst crisis of Reagan's presidency.

A key question of the hearings will be whatReagan knew, Inouye said on NBC-TV's "Meet thePress."

Inouye said he has found no evidence whatsoeverthat the President knew about the diversion ofmoney from the arms sales.

The senator was asked whether his review ofexcerpts of Reagan's diaries led him to believethe President was aware of the effort to raisemoney to supply arms to the contras.

"The President was aware that monies were beingraised to provide arms for the contras," Inouyereplied.

Inouye added that he believed the Presidentknew about the fundraising effort at a time whenCongress "had expressed its intention that fundsshould not be spent for arms for the contras."

But Sen. Warren Rudman (R-N.H.), vice-chairmanof the Senate panel, said, "There's a differencebetween public and private funds...and that's, ofcourse, the one issue that we have yet to hone inon."

Reagan has said he knew nothing about thediversion of arms sales profits to the contrasduring a time when Congress had banned U.S. helpfor the guerrillas. He also has said he met withdonors to a private foundation set up to raisemoney for the contras, but said he thought thefoundation run by Carl R. "Spitz" Channell wasonly seeking the money to pay for pro-contratelevision ads.

The President repeated that contentionyesterday, speaking to reporters before a speechon Ellis Island in New York.

Reagan said he was aware of the private aidnetwork, "but there was nothing in the nature of asolicitation by the Administration, to myknowledge, of anyone, to do that."

"All I know was that there were people...justas there were people who have done that for othercauses. I have no detailed information. I did knowthe people I met with, to thank, because they hadraised money to put commercials on television tourge the Congress to support the contras."