Two days before Attorney General Edwin Meese III told a nationally televised news conference last November that the U.S. government had not been involved in a 1985 Israeli arms shipment to Iran, he was told by White House aide Oliver L. North that the CIA had directly participated in the deal, according to handwritten notes of their meeting.

That discrepancy between what Meese said in the news conference and what he had learned during a weekend fact-finding inquiry into the Iran-contra affair is one of many subjects on which the attorney general is expected to face questioning this morning when he testifies before the congressional Iran-contra committees.

During the hastily called Nov. 25 news conference in the White House briefing room, Meese disclosed that profits from direct U.S. arms sales to Iran had been diverted to the Nicaraguan contras but stated that Israel's two 1985 shipments "did not involve, at that time, the United States."

Terry Eastland, a spokesman for Meese, said yesterday that the attorney general used the phrase "not involved" to mean the U.S. government had not "organized the transaction. It was an Israeli project."

As the congressional hearings enter their 11th week, Meese's testimony could shed light on several of the remaining mysteries in the affair, including what he told President Reagan about his inquiry that led the president to fire North and accept the resignation of North's boss at the National Security Council, Rear Adm. John M. Poindexter.

Committee members are expected to lead Meese through a step-by-step explanation of his inquiry, which began Nov. 21, after Meese was alerted to disagreements between Secretary of State George P. Shultz and Director of Central Intelligence William J. Casey concerning Casey's testimony about the November 1985 shipment.

Sen. Warren B. Rudman (R-N.H.), vice chairman of the Senate panel, has called the Meese fact-finding team "the gang that couldn't shoot straight," and other committee members have attacked the way Meese and his handpicked deputies handled the discovery of a memorandum in North's files that made reference to the diversion of proceeds from the arms sales to support the Nicaraguan contras.

One question is what Meese asked Poindexter in the days before his resignation about the diversion and the president's knowledge of the scheme.

Poindexter testified that Meese met with him for only five minutes on Nov. 24 to discuss the explosive memo, but never asked who had approved the diversion or whether the president was involved in the decision.

Meese is also expected to be questioned about his role in delaying FBI and U.S. Customs Service investigations into Southern Air Transport following the Oct. 5 shootdown over Nicaragua of a C123 cargo plane on which Southern Air had performed maintenance. The plane was part of a private, North-organized airlift to the contras run by retired major general Richard V. Secord.

Meese told the Senate intelligence committee last December that Poindexter called him last Oct. 30 and requested a delay in the inquiry, expressing fears that it would expose Southern Air's involvement in the Iran arms shipments.

Meese made no mention during his testimony of any FBI or Customs investigation of Secord. But a Nov. 14 North memo to his files refers to suspension of an FBI "investigation of Maj. Gen. Secord's involvement in support of the Nicaraguan resistance," and a statement from Associate Attorney General Stephen Trott that "the Secord and Southern Air involvement with the Iran covert action had been the subject of a discussion between Trott and the attorney general."

The FBI investigation was held up for several weeks by then-FBI Director William H. Webster, who told the Senate intelligence committee that he authorized the investigation to resume on Nov. 20.

On Nov. 21, North testified, he may have had a direct conversation with Meese, which North said must have been about the Southern Air inquiry. North said he was still concerned that "pursuing the investigation was going to create a liability for a potential hostage release."

At the time, no discussion of releasing hostages was pending, and the entire Iran initiative had just ecome the subject of the Meese fact-finding inquiry. North himself was in the midst of destroying records associated with the secret NSC support of the contras, which had yet to surface.

In a private deposition to the committees, North's deputy, Marine Lt. Col. Robert L. Earl, said North told him on Nov. 21 that he had just talked with the attorney general and learned that he had "24 or 48 hours," according to Rep. Peter W. Rodino Jr. (D-N.J.), who said he had seen a transcript of Earl's sworn testimony.

Earl also said that North had told him that the "attorney general responded that he did not know whether {North} could have that much time," according to Rodino.

Yesterday, in response to questions about Meese's appearance, Eastland told reporters Meese plans to testify that he was uninformed about most aspects of the Iran arms sales. Meese has stated previously that he knew nothing about the controversial November 1985 transfer of 18 U.S.-made Hawks from Israel to Iran until Nov. 22, 1986, when he received relevant details from Shultz and then-CIA general counsel Stanley Sporkin as part of his fact-finding inquiry.

At the Nov. 25 news conference, Meese not only said that the United States was not involved, but also stated that Reagan did not learn details of that shipment until February 1986, and "did not have complete information at the time."

But Shultz told Meese on Nov. 22 that "the president said he knew of it, but didn't understand it as arms for hostages but as part of a larger plan," according to the notes of that conversation taken by Assistant Attorney General Charles J. Cooper.

The main focus of the Nov. 25 press conference, however, was his stunning disclosure that money had been diverted to the support of the contras from the U.S.-Iran arms sales of 1986.

According to notes of another meeting -- this one between Meese and North on Nov. 23 -- North said he hoped that information about the diversion would not be revealed. "If this doesn't come out, {the} only other is November Hawks deal -- think someone ought to step up and say this was authorized in November," according to the notes of John Richardson, assistant to Meese.

The phrasing suggests that North meant the only other "problem" besides the diversion was the Hawk shipment, which was described in a Dec. 5, 1985, presidential finding that belatedly authorized it as an arms-for-hostages deal.

In questioning North about the diversion, Meese asked who else knew about it, but did not ask whether it had been authorized, and if so by whom, according to Richardson's notes.

Meese did ask North whether he had discussed use of the "residuals" from the arms sales with Reagan, and was told that Poindexter was North's "point of contact" with the president. But when the attorney general met with Poindexter the next day, he did not follow up, according to Poindexter.

The notes record North saying that he "went to talk to RR re: strategic relation & w/RR it always came back to hostages." North added: "Terrible mistake to say RR wanted the strategic relationship b/c RR wanted the hostages."

Meese, who was in a fact-finding role, interjected: "He {RR} talked about both."

Senate committee Chairman Daniel K. Inouye (D-Hawaii) said Meese will be followed by former White House chief of staff Donald T. Regan and Secretary of Defense Caspar W. Weinberger.

The hearings will be suspended Wednesday morning to enable Meese and panel members to attend a memorial service for secretary of Commerce Malcolm Baldrige, who was killed in an accident during rodeo practice Saturday. Inouye said the committees still hope to complete the hearings by Aug. 7.

The committees also announced that four CIA witnesses would testify in closed session: Alan Fiers, chief of the Central American task force; Clair George, deputy director of operations; Duane Clarridge, head of the counterterrorism center, and John N. McMahon, former deputy director.