Ken W. Clawson, 63, the White House communications chief during the final months of the Nixon administration and a zealous loyalist to the embattled president before and after his 1974 resignation, died yesterday at Ochner Hospital in New Orleans after a heart attack.

Mr. Clawson, a former reporter on the national staff of The Washington Post, joined the Nixon administration as deputy director of communications in February 1972, less than five months before the break-in at Democratic National Committee headquarters in the Watergate complex that ultimately led to the president's resignation. Over the next 30 months, he built a reputation as one of Nixon's most aggressive defenders, even as the Nixon presidency disintegrated in the face of an unfolding scandal that became known by the catch-all word "Watergate."

At the end, "there were so few of us left who were still loyal to the Old Man. . . . Tears were streaming down my face as I watched the helicopter take off," Mr. Clawson wrote in a 1979 article for The Washington Post, recalling the president's departure from the White House lawn after quitting the presidency. Mr. Clawson later accompanied Nixon to San Clemente, Calif., where he remained on the former president's staff until November 1974.

Savvy and well-connected in the Washington press corps, Mr. Clawson joined the White House staff with a mandate that he described as seeing to it that the administration's position received adequate coverage in the media. Relations between the White House and the media had been testy, at best, and Mr. Clawson's marching orders were to counter what the administration perceived as an anti-Nixon bias. He was said to have cultivated a "tough guy" image in his role of White House defender. "I'm just one of Richard Nixon's spear carriers and proud of it," Mr. Clawson told the New York Times.

According to Marilyn Berger, a Post reporter at the time, Mr. Clawson boasted to her in 1972 that he was the author of a letter that had damaged the candidacy of Sen. Edmund S. Muskie (D-Maine) in the New Hampshire Democratic presidential primary. The letter, addressed to the Manchester Union Leader newspaper, quoted Muskie as having used the racially disparaging reference "Canucks" in a letter to describe French Canadians.

Mr. Clawson later denied Berger's recollection of the conversation, saying she must have misunderstood him.

Mr. Clawson was known to have telephoned Walter Cronkite in the middle of a CBS Evening News broadcast to demand that a White House comment on a particular story be aired before the broadcast ended. Members of the White House press corps said he threatened to get them in trouble with their editors if they produced stories that he considered unfair to the president.

Mr. Clawson was promoted to director of communications in January 1974. In this role, he instituted regular informal late-afternoon gatherings in his office between administration officials and a small group of reporters. Drinks and snacks were served, along with paper napkins bearing the inscription, "Cocktails with Ken."

Guests included presidential son-in-law David Eisenhower, White House Chief of Staff Alexander M. Haig Jr., White House counselors Ann Armstrong and Dean Burch and the then-presidential speech writer Patrick Buchanan. Care was always taken to invite a few reporters considered unfriendly to the administration, and the on-the-record sessions were often described as free-swinging.

On the morning of Aug. 9, 1974, Mr. Clawson recalled in his Post article of 1979, "The White House limousine that normally came for me at 7 arrived at my McLean home at 9 a.m. to take my wife and me to witness the final act that would make the Nixon presidency a thing of history."

In the East Room of the White House, "the press was on one side of the room and the Cabinet officers and White House staff on the other. I knew that among them were too many that I felt were traitors to the Old Man. People such as William Simon, William Baroody, Dean Burch, James Schlesinger, Alexander Haig, who had done everything in their power to push the Old Man into doing what he was about to do. . . .

"I couldn't help wishing that Colson, Ehrlichman and Haldeman were still around. They were strong and presented a special leadership. They could have talked him into staying and fighting."

On the previous day, when Haig told him the president was going to announce his resignation, Mr. Clawson recalled that "I protested as I had all along. . . . After my talk with Haig I called the communications staff together. We had a final drink from the whiskey that remained from the 89 sessions of Cocktails with Ken. I raised my glass and said 'To the President.' We drank in silence, while some cried."

Mr. Clawson was born in Monroe, Mich., and graduated from Bowling Green State University. His first job in journalism was with the Monroe Evening News. From there he went to the Toledo Blade newspaper in Ohio, where he became national labor reporter.

In 1967, he won a Nieman Fellowship at Harvard University, with the support of letters of recommendation from James R. Hoffa of the International Brotherhood of Teamsters, Walter Reuther of the United Autoworkers and management executives of General Motors.

He joined The Washington Post as an editor on the national desk after completing his Nieman year at Harvard, then as a reporter he covered the Justice Department.

In 1975, Mr. Clawson suffered a partially paralyzing stroke from which he never completely recovered.

With his wife, Carol, he later moved to New Jersey and later to New Orleans.

In addition to his wife, of New Orleans, survivors include three children, Ken David Clawson II of Berryville, Va., Geoffrey Clawson of McLean, and Karen Kelchak of Cumberland, Md.; his mother, Lilaf Clawson of Monroe, Mich.; a sister; and six grandchildren.

CAPTION: Ken Clawson, shown in his basement study, was among the most tireless of President Richard M. Nixon's defenders.