The congressional Iran-contra committees, reporting on one of the most exhaustive investigations into the conduct of U.S. foreign policy in the nation's history, yesterday charged the administration with "disdain for the law" and assigned the "ultimate responsibility" for the affair to President Reagan.

In an elaborately documented Senate-House majority report approved by 15 Democrats and three Republicans, the committees asserted that the behavior of a "cabal of zealots" who controlled administration behavior in the Iran-contra affair was at times at odds with "democratic governance," and they suggested that Reagan had failed in his duty under the Constitution to "take care that the laws be faithfully executed."

In a toughly worded commentary on Reagan's actions after secret arms sales to Iran were disclosed last November, the committees noted that the president made many public statements that turned out to be "wrong." At the same time, it said, Reagan "has yet to condemn {the} conduct" of senior advisers who "lied, shredded documents and covered up their actions" to conceal activities they thought were in line with his policies toward Iran and Nicaragua.

Reagan did not respond yesterday to that invitation to condemn his former aides. Instead the White House reacted cautiously to the report, turning the other cheek to the committees' harsh criticism. The report shows that "the president did not violate any laws," the White House said in a prepared statement which stressed that there is no new information that the president knew of the diversion of proceeds from U.S.-Iran arms sales to aid the contras.

"This report is but another step in the investigatory process, but it does culminate the long summer of self-examination for America and for the administration, and now we are through with it," the statement declared.

The 427-page majority report, the result of 10 months of interviews and fact-finding and 11 weeks of televised public hearings, was tougher on Reagan than many had expected. It went beyond last February's findings of the Tower commission, which primarily faulted the National Security Council staff for failing to keep the president adequately informed, and criticized Reagan's management style.

Fundamental constitutional and legal issues were involved, not abstractions or trivial matters of management, according to the new report. "In the Iran-contra affair, officials viewed the law not as setting boundaries for their actions, but raising impediments to their goals," it said. "When the laws and the goals collided the law gave way," it added.

Among the abuses cited was the use of private funds, or monies solicited from foreign governments, to run the contra war -- a practice that the report said clearly collided with the Constitution's mandate that Congress hold the "power of the purse."

In one of its revelations, the report discloses that at a meeting in June 1984, Secretary of State George P. Shultz conveyed to Reagan and other top officials the opinion that allowing the United States to act as a conduit for third-country contributions to the Nicaraguan contras when Congress refused to provide the money directly would be "an impeachable offense." Shultz said he had been told this by then-White House chief of staff James A. Baker III. Unbeknownst to Shultz, the administration subsequently served as a conduit for substantial Saudi contributions to the Nicaraguan rebels.

Although a majority of the five Republicans on the Senate committee signed the main report, two Republican senators and all six Republicans on the House panel issued a dissent calling the main conclusions "hysterical."

The minority dissent concluded that although the administration made mistakes, "there was no constitutional crisis, no systematic disrespect for 'the rule of law,' no grand conspiracy and no administration-wide dishonesty or coverup." {Details, Page A25.}

But Sen. Warren B. Rudman (R-N.H.), vice chairman of the Senate select committee, dismissed the minority document as "pathetic," charging that its authors "separated the wheat from the chaff and, unfortunately. . . printed the chaff." He added: "I think the minority evidently believes that Republicans somehow don't want the truth laid out. My Republican constituents want the truth laid out."

Despite the strength of its criticisms, the majority report acknowledges that the investigation did not uncover the whole story. Many documents were destroyed, and several key witnesses were either dead or unavailable.

The committees did not rule out the possibility that the administration witnesses who testified before them told a prearranged cover story.

"The committees cannot even be sure whether they heard the whole truth or whether {the late CIA Director William J.} Casey's 'fall guy' plan was carried out at the public hearings," the report said. Former White House aide Oliver L. North, who described Casey's "fall guy" plan in his testimony, said it called for North and former national security adviser John M. Poindexter to take the blame if the Iran-contra events were revealed.

Critics of the committees' inquiry including some members of the two panels and their staffs have said that the investigation failed in several respects. They cited the imposition of a deadline, the failure to question witnesses adequately and the refusal to confront Reagan personally with questions about his role as weaknesses in the investigation.

A major focus of the report is whether the Reagan administration and its highest officials comported themselves within the framework of law and the Constitution.

The committees deliberately avoided saying whether any individuals acted "with criminal intent" or were "guilty of any crime," leaving that determination to independent counsel Lawrence E. Walsh. But they made clear that, in a broader sense, many laws had been violated.

For example, U.S. participation in the November 1985 shipment of Hawk antiaircraft missiles to Iran violated laws requiring the president to issue a finding, or authorization, for such intelligence activities in advance and violated the arms export control act's provisions controlling the transfer of U.S.-made arms by third parties, the report notes.

The report documents elaborate efforts by Reagan, Rear Adm. Poindexter, Robert C. McFarlane, North, Casey and others to hide their knowledge of the 1985 shipments after realizing that they could have been illegal.

The report describes Reagan's statements in November 1986, in which he denied knowlege of the questionable 1985 shipments. It also says: "The record makes clear that North, Poindexter, Casey and others were engaged in a deliberate attempt to falsify the facts concerning the November 1985 . . . shipment" of U.S. arms to Iran.

The committees charged that administration officials' testimony to Congress in November 1986 that the U.S. government had no knowledge of the 1985 Hawk shipments at the time they were happening "obstructed congressional investigations."

Regarding the covert, White House-run program of support for the contras at a time when Congress had banned U.S. aid, the report says the program "evaded the Constitution's most significant check on executive power: The president can spend funds on a program only if he can convince Congress to appropriate the money."

The report suggests that both secret support for the contras through the enterprise of North and retired major general Richard V. Secord and the solicitation of funds from third countries to help the contras were illegal.

The committees noted that "false statements to Congress are felonies if made with knowledge and intent. Several administration officials gave statements denying NSC staff activities in support of the contras, which North later described as 'false' and 'misleading, evasive and wrong.' "

The diversion of proceeds from the U.S.-Iran sales via Secord's "enterprise" represented a "misappropriation of government funds derived from the transfer of U.S. property {the American arms sold to Iran}" and was a "flagrant" violation of the Boland Amendment, which restricted U.S. aid to the contras from 1984 to 1986. The enterprise, the committees made clear, "functioned at North's direction."

The committees rejected the contention of North and of former national security adviser Poindexter that the Boland Amendment did not apply to the NSC.

"Under the view of North and Poindexter, a president whose appropriation requests were rejected by Congress could raise money from private sources or third countries for armies, military actions, arms systems and even domestic programs. That is the path to dictatorship," the committees said.

The committees were even harsher in condemning Poindexter's rationale for not telling the president about the diversion of funds to aid the contras. Poindexter said he wanted to give "deniability" to the chief executive. But such thinking, they said, "is inconsistent with democratic governance."

The report is also sharply critical of practices that did not violate any law, particularly of Casey's willingness to doctor intelligence to suit his policy preferences. The report cites several instances where Casey offered as intelligence findings information that actually reflected his personal preference, not any objective analysis or reporting. {Details, Page A27.}

Committee spokesmen said yesterday that the report does not contain any dramatic new "smoking gun" that could endanger the Reagan presidency. Scattered through it, however, are many new pieces of information and extensive new details that provide the fullest account yet of the affair.

The report reveals:The idea of using funds generated by arms sales for other secret purposes was first discussed by North and Israeli counterterrorist special Amiram Nir much earlier than previously revealed. It suggests that discussions between them led to an elaborate scheme to finance covert counterterrorist and other activities, including helping the contras.

The report discloses that North and Nir met on Nov. 14, 1985, to dicuss a variety of future U.S-Israeli covert operations that could "require at least a million dollars a month," according to the committees. They met again five days later, and North's notes reflect that they would require a source of "op{erational} funds."

On Nov. 20, North channeled $1 million of Israeli funds to Secord for use in shipping American-made Hawks to Iran. But $800,000 of that was diverted to support the contras and for other purposes -- the first such diversion of funds.

On Dec. 6, according to notes of an Israeli official at the military purchasing mission in New York City, North said he intended to use profits from planned shipments of arms to Iran to support the contras.

In January, Nir came to Washington with a proposal for joint covert operations that would gather intelligence on terrorist groups, seek the release of hostages, initiate and finance propaganda efforts -- all to be funded by the excess profits from the sale of 1,000 TOW antitank missiles to Iran.

This sequence of events raises the possibility that the diversion of arms-sales profits to the contras was actually part of a larger scheme to set up a secret, off-the-books covert action capability beyond congressional scrutiny -- the "off-the-shelf" intelligence capability that Casey once described to North, according to North's testimony. But the committees' report does not speculate on this possibility. Interference by North in law enforcement investigations by Customs and FBI agents checking into the contra-resupply network was more extensive than has been reported. North contacted Customs Commissioner William von Raab in August 1986, to complain about a Customs investigation into whether Maule Aircraft of Macon, Ga., had shipped four light aircraft to Central America in violation of the export control laws. North mentioned that the president of the company was a "close friend of the president." The call delayed the investigation for several months. North, in 1986, contacted Oliver {Buck} Revell, executive assistant director of the Federal Bureau of Investigation, and suggested the government investigate the plaintiffs in a private law suit against Secord, Secord's business partner Thomas Clines and others. The plaintiffs were a group of activists opposed to Reagan administration policy in Central America. Revell "told him that the FBI did not engage in that type of investigation," according to the report. North's personal notebooks reveal that he was actively guiding the work of Army Col. James Steele, the U.S. military attache in El Salvador during the secret resupply effort to aid the contras. It was previously known that Steele consulted occasionally with participants in the resupply effort, but only to monitor their activities. There was no previous evidence of direct North-Steele dealings. The report's revelations -- contained in a footnote -- show Steele's active involvement in the operation itself, and demonstrate again that North was much more deeply involved in running the resupply effort than the administration has acknowledged.

Newly reported testimony challenges statements made to the committees by Duane (Dewey) Clarridge of the Central Intelligence Agency. Both the CIA chief and deputy chief in Portugal recall a Nov. 23, 1985, "eyes only" cable to the CIA's counterterrorism expert Clarridge advising him that planned flights from Lisbon to Iran would contain U.S. Hawk antiaircraft missiles.

Clarridge denied to the committees that he received the cable or knew there were Hawk missiles involved until 1986. The cable was missing from those turned over to the committees by the CIA.

North testified that shortly after the shipment, if not before, he had told Clarridge that the true cargo was weapons rather than "oil drilling equipment," the cover story. There is "some evidence" that North's private associate Secord may have been brought into the November 1985 Hawk shipment via Portugal in order to pay Portugese officials to clear the flights. "One of the persons with whom Secord was working, an official of a European arms company, reportedly atempted to bribe an official of the government {of Portugal} to obtain the necessary clearances, and there are references to Secord having spent substantial sums {there}." Previously undisclosed transcripts of meetings with Iranian intermediaries at Secord's offices in Vienna, Va., show that a senior Iranian suggested that "the United States join Iran in trying to raise the price of oil." North responded that oil prices were "naturally low," but said the United States and Iran had "similar interests with respect to oil."

At the end of the report, the committees listed 27 recommendations, but said that the principal ones were "not for new laws but for a renewal of the commitment to constitutional government and sound processes of decision-making."

Congress, the report said, "cannot legislate good judgment, honesty or fidelity to law." But it said some changes relating to the oversight of covert operations could make the system function better.

It urged legislation requiring the president to sign the "finding" authorizing a covert action before the operation begins. The first such authorization signed by Reagan to cover the 1985 Hawk shipment to Iran was not signed for some 15 days after the operation took place.

It recommended a tightening of laws governing presidential notification to Congress of an intelligence operation to require that Congress be told within 48 hours. Current law requires "timely" notification.

The attorney general, it said, should receive a copy of all intelligence findings. Such a procedure was not followed when Reagan signed a finding authorizing the November 1985 Hawk shipment in December of that year, according to testimony of Attorney General Edwin Meese III.

The committees recommended that "members of the NSC not engage in covert actions." They noted that although the NSC was set up to provide "advice to the president," there is no specific statute prohibiting it from engaging in intelligence operations of the kind that made it the center of the Iran-contra affair.

The committees recommended against consolidating the House and Senate intelligence committees, a proposal contained in the report of the Tower commission and in the minority report issued by the eight Republicans.

The committees also recommended that "presidents adopt as a matter of policy the principle that the national security adviser to the president. . . should not be an active military officer. . . . " Reagan recently named Lt. Gen. Colin Powell his sixth national security adviser.