The Iran-contra hearings, a gripping drama that played to a national audience for 11 weeks, ended their public phase yesterday with the chairman of the Senate select committee declaring that the testimony had exposed a "chilling story" and a "flawed policy kept alive by a secret White House junta, despite repeated warnings and signs of failure."

"I believe these hearings will be remembered longest not for the facts they elicited, but for the extraordinary and extraordinarily frightening views of government they exposed," said Sen. Daniel K. Inouye (D-Hawaii). He then rapped his gavel for the last time and adjourned the House and Senate panels.

Those combined hearings were unprecedented in the history of congressional investigations. But unity was absent yesterday from the concluding statements of the four committee leaders, two Democrats and two Republicans, except in one important respect: None of the four criticized President Reagan directly for his role in the Iran-contra affair.

The two Republicans also emphasized their view that the evidence had not implicated the president in either the diversion of Iranian arms sales proceeds to the Nicaraguan contras, or in a cover-up after the U.S. dealings with Iran were exposed.

In a hint of the partisan warfare still ahead when the two committees write their report, Rep. Dick Cheney (R-Wyo.), vice chairman of the House select committee, criticized other committee members and the news media for their "apocalyptic rhetoric about these events, most of it unjustified."

"If there ever was a crisis, which I doubt, it ended before these committees were established," Cheney said, describing the controversy as a "traditional struggle between the president and Congress over policymaking and implementation."

Cheney's counterpart on the Senate committee, vice chairman Warren B. Rudman (R-N.H.), was harsher in his closing remarks. He said that extremely serious abuses had occurred, but blamed them primarily on two officials of the National Security Council: former national security adviser Rear Adm. John M. Poindexter and former NSC aide Lt. Col. Oliver L. North, both of whom admitted destroying records and misleading Congress.

These men, Rudman said, "flouted virtually every standard operating procedure that exists . . . . These actions, and the attitudes they represent, are antithetical to our democratic system of government. They cannot be justified by passion, patriotism, appropriate concern over the expansion of communism in Central America or a legitimate dismay over the policies enacted by Congress."

At the same time, he declared that the allegation that Attorney General Edwin Meese III, who conducted the "fact-finding" probe that led to the discovery of the diversion scheme, "was himself involved in the cover-up is unfair and false."

For his part, Rep. Lee Hamilton (D-Ind.) blamed no particular individual for the Iran-contra abuses. He defended the committees' work as "an essential part of the self-cleansing process" and said that more depositions will be taken in closed session in the weeks ahead.

"Further public hearings are possible if new evidence warrants it," Hamilton said.

The public testimony ended almost precisely on the schedule set by the committee leadership before the hearings opened, and Inouye made a point yesterday of saying that they had stuck to the schedule. But some Democrats on the House committee have expressed their unhappiness with the pressure to conclude the hearings in time for Congress' summer recess on Friday.

Some members also have said they feel swamped by the massive amount of information collected by the committees, including 1,059 exhibits, 200 depositions and 41 days of testimony from 29 public witnesses, and would have liked more time between hearing days to prepare themselves for the sessions.

By the end of the public testimony, the committees had heard from three Cabinet officers, two former national security advisers, a former White House chief of staff, several NSC staff members, a former Central Intelligence Agency station chief and one of the Justice Department lawyers who helped conduct the fact-finding probe last November. They also heard from the men who ran the secret "enterprise" that North created to carry out covert activities.

Nonetheless, Inouye said in his closing statement, "we may never know with precision and truth why it happened."

The final witness yesterday was Defense Secretary Caspar W. Weinberger, for the second day. During a concluding three hours of questioning:Weinberger said he was unaware that the CIA had reimbursed the Army for more than $5 million worth of TOW antitank missiles by writing a series of checks in the identical amounts of $999,999, an apparent attempt to avoid a congressional reporting requirement.

A House Armed Services Committee report on the transfer of the TOW missiles, which were destined for Iran, pointed out this same fact and noted that the CIA was required to report the activity to Congress only when the amount exceeded $1 million.

Rep. Jack Brooks (D-Texas) said it looked to him as if "something's a little fishy." Weinberger acknowledged that it was "clumsy" to operate that way, but added he knew nothing about the CIA's unusual payments until Brooks informed him yesterday morning. He promised to send a directive to the department to report receipts that suggested a reporting requirement was being evaded. Weinberger, who complained Friday that he was not kept up to date by the NSC staff on the 1986 Iran initiative and received information about what was happening through foreign intelligence sources, told the committees yesterday that he himself had not shared what he knew about the operation with the chairman of the Joint Chiefs of Staff until "July or August" last year.

Asked by Sen. Sam Nunn (D-Ga.) whether the May 1986 sale of U.S. Hawk missile parts had helped Iran militarily, Weinberger responded that the shipment "wasn't to make the Hawks operational . . . but they obviously needed and wanted some spare parts."

Nunn, referring to the possibility of U.S. participation in the Persian Gulf war, responded: "They obviously wanted to operate better . . . or they wouldn't have needed any materiel from us." In response to questions from Sen. James A. McClure (R-Idaho) and House Majority Leader Thomas S. Foley (D-Wash.), Weinberger said that he heard only "reports" and rumors that Israel had sold arms to Iran even before mid-1985, when the U.S. government was approached about replenishing U.S.-made weapons that could be transferred to Iran in the hope of securing the release of hostages. During this period, the United States had an arms embargo against Iran, and was asking its allies to honor it.

McClure referred Weinberger to a still-classified Nov. 21, 1986, State Department memo that apparently referred to this matter, and that Weinberger said he had not seen before. McClure related this memo to a statement Secretary of State George P. Shultz made on Nov. 10 suggesting that the Israelis "sucked us up into their operation, so we could not object to their sales to Iran."

When Weinberger was asked what he thought of a plan North attributed to the late CIA Director William J. Casey to use the proceeds from the sale to set up an "off-the-shelf, outside-the-system" covert organization, the defense secretary replied: "I think part of the problem {with that sort of thing} has been exemplified in the last few months . . . . I am not in favor of unofficial, private people carrying out governmental activities."

The closing statements of the House and Senate panel leaders suggested that partisan disagreements over the interpretation of facts probably lie ahead. One committee source said yesterday that the statements were an attempt to find "common denominators." But he noted that there are "still lots of pieces out there."

Cheney, while saying that "mistakes" were made, stressed that there was no evidence that Reagan knew anything about the diversion of funds to the contras. And, he said, the hearings have "demonstrated conclusively, in my opinion, that the president has indeed been telling the truth."

Rudman and Cheney both praised the president for what they called unprecedented cooperation in waiving executive privilege to allow the committees access to White House documents, and to direct Cabinet members to answer questions about their conversations with him. He also allowed committee counsel to read pertinent portions of his personal diaries, which have not been released publicly in any form.

Rudman also noted that the president had approved the inquiry by Meese last Nov. 21 that resulted in the discovery the following day of the North memorandum containing a reference to the diversion.

Rudman called the diversion "improper and possibly illegal" -- a view that could also form the core of any conspiracy case that independent counsel Lawrence E. Walsh, who has been investigating the affair since December, may bring. If such a case is brought, defendants could argue that they were not conspirators because they acted under authority or that Reagan's approval was not necessary. But Rudman said that Shultz, Weinberger, Regan and Meese all testified that Reagan would not have approved the diversion if he had known about it.

Cheney stressed two themes: He urged his colleagues "to resist the temptation to enact legislation designed to guarantee that no future president makes mistakes that Ronald Reagan made in this instance." And he called for Congress to control classified information better, perhaps by creating a smaller joint House-Senate intelligence committee to replace the two existing committees and by taking "swift and appropriate disciplinary action against members who leak."

Staff researcher Michelle Hall contributed to this report.