Michael K. Deaver, former White House deputy chief of staff and a close friend of President Reagan, was convicted yesterday of lying to a congressional subcommittee and a federal grand jury about his contacts as a lobbyist after leaving the White House.

Deaver, 49, was found guilty of three of five perjury counts and faces a possible sentence of 15 years in prison and a $22,000 fine.

The verdict, reached after 27 hours of deliberations, made Deaver the highest-ranking present or former Reagan administration official to be convicted of a crime. It also marked the first successful jury trial prosecution by any of the independent counsels named to investigate corruption among senior government officials.

"I'm obviously very disappointed," a pale and drawn Deaver said on the steps of the U.S. Courthouse moments after his conviction. "But at the same time I know in my heart that I'm innocent."

Deaver did not respond to questions about whether he will seek a presidential pardon. Some White House officials have said privately that, of all the former White House aides under investigation or indictment, Deaver would have been most likely to have received a pardon until the recent publication of excerpts from his forthcoming book, "Behind the Scenes."

It has reportedly infuriated Nancy Reagan with its sometimes unflattering views of the Reagans and has raised doubts that the president will clear Deaver's criminal record. In any event most officials said the president probably will not act as long as the case is being appealed.

"Nancy and I are sorry to learn of the jury's decision in Mike Deaver's trial," Reagan said in a statement. "He has been a longtime friend and has served with dedication." The president said he could not comment further, citing the likelihood of appeals.

Deaver's lawyers, who in a controversial move opted to put on no defense, immediately announced they will move for a new trial and, if unsuccessful, will appeal.

"We didn't put on a defense because we didn't think we had to," said Herbert J. Miller Jr., regarded as one of Washington's premier criminal lawyers. "The jury verdict suggests I may have made a mistake."

Independent counsel Whitney North Seymour Jr., the prosecutor, said in a statement that the verdict "shows the American system of justice at its best. A jury of conscientious citizens selected from the community at random, guided by an experienced and impartial trial judge, has resoundingly reconfirmed the constitutional tradition of equal justice under law."

The jury of nine Democrats, two Republicans and one unregistered District resident filed back into Courtroom No. 2, the art-deco style courtroom that was the scene of the Watergate trial 13 years earlier, at 2:30 p.m. to announce its verdict.

Deaver stood with his hands clasped behind his back as the jury foreman, Barrington B. Bell, began to read the verdict. Deaver's 17-year-old daughter, Amanda, collapsed into the embrace of her mother, Carolyn, who was sitting at her side.

Her father looked at her, forcing a smile. Later she and her mother hugged Deaver after U.S. District Court Judge Thomas Penfield Jackson set sentencing for Feb. 25 and left the room.

"We just went by the evidence . . . . It was quite clear," said one juror, Janice Mae Hale, a Safeway food service manager. Another member of the jury, Jesse Miller, a Postal Service manager, said he was surprised when Deaver opted to make no defense.

Would his testimony have made a difference? "I couldn't say," Miller said. "The only thing we could go on was the evidence we had."

The jury found Deaver guilty of lying on three issues: to a congressional subcommittee in 1986 about his role in arranging a visit by a South Korean trade envoy to the Oval Office; to a grand jury the next month about efforts to contact administration officials on behalf of Trans World Airlines, and to the same grand jury about contact on behalf of a Puerto Rican tax benefit.

It cleared him of a charge of lying about his contacts with seven White House officials on behalf of various clients and of lying about his role while still in the White House in helping shape the administration's policy on acid rain with Canada.

Carole L. Birckhead, a program manager for the Army Corps of Engineers, said the jury took so long to reach its verdict because it went back through each of the five counts, checking hundreds of pages of documents and testimony before voting on any issue. "There was no question about those counts on which we found him guilty," she said.

Birckhead said that Seymour's closing argument was extremely helpful to the jury in sorting out the evidence. "The prosecution really tied it together," she said.

The failure of the government to produce some key witnesses, such as former transporation secretary Elizabeth Hanford Dole, didn't matter, Birckhead said, because "we could see a paper trail" indicating that Deaver had contacted the officials.

The decision marks the nadir of the career of a man who for the first five years of the Reagan presidency was at the center of power in Washington.

Deaver was one of what one witness called the "troika" of three presidential aides -- then chief of staff James A. Baker III and then counselor Edwin Meese III were the others -- who controlled access to Reagan and helped shape his policies. Time magazine once hailed him as the "vicar of visuals" for his role in helping use television to mold Reagan's image.

It was a singular victory for Seymour, the patrician Park Avenue lawyer who was the first independent counsel appointed under the 1978 Ethics in Government Act to bring a criminal case to trial.

Deaver left the White House on May 10, 1985, and despite the urging of one friend who suggested he needed a "six-month vacation" he plunged almost immediately into forming Michael K. Deaver & Associates, a lobbying firm.

The firm quickly signed up a number of major corporations and foreign countries as its clients. And, as the trial disclosed, those relations almost immediately got Deaver into trouble.

Seymour was appointed to investigate allegations that Deaver violated the federal ethics act, which proscribes the type of contacts that high government officials may make after they leave government. Seymour told the jury, in his final argument, that Deaver was never charged with violating the act because he blocked Seymour's inquiry into those allegations when "he lied."

Thwarted by Deaver's hazy memory of his early lobbying efforts and by a law that even Jackson "I'm obviously very disappointed. But. . . I know in my heart that I'm innocent."

-- Michael K. Deaver

said is difficult to understand, Seymour turned to the perjury statute and charged that Deaver lied to both a House subcommittee investigating Deaver's lobbying and to the grand jury that did the same.

Deaver had entered the trial planning to offer what lawyers described as a novel and controversial defense. He would claim that alcoholism had so blurred his memory that he was probably telling the truth when he said he could not remember the contacts he was accused of failing to recall.

But his lawyers, reacting to adverse rulings by Judge Jackson and their belief that the prosecution had made a weak case, decided not to offer any defense. That decision left them with so little evidence of Deaver's drinking on the record that Jackson blocked them from referring to the issue in their final arguments. The judge also instructed the jury not to consider it.

As the seven-week trial went on, Deaver had his share of troubles outside the courtroom as well. He had to be hospitalized twice for kidney stone problems, once forcing a week's recess.

The weeks of testimony provided a rare glimpse into the world of Washington's highest-paid lobbyists, with corporate executives telling of their eagerness to have such a close friend of the president as a member of what one called their "team" in the capital.

Seymour alleged that Deaver did little more than make a few telephone calls for his fees, which ranged from $250,000 for most corporate clients to $475,000 for Korea, his most costly contract. Deaver countered that he and his staff did long-range "strategic planning" and were not the "quick-fix" specialists that Seymour portrayed.

While Deaver had made a point of saying he would never trade on his relationship with the president, Seymour charged that Deaver had attempted to cash in on that friendship.

Some witnesses made it clear that Deaver's closeness to the president and Nancy Reagan was among his biggest assets. A Boeing Co. executive testified he had argued for Deaver's selection over Lyn Nofziger, another former Reagan aide, to help win a contract for a new presidential Air Force One because "Mr. Deaver was closer to the personal tastes and preferences of the president."Staff writer Nancy Lewis contributed to this report.