Pete Conrad, who flew to the Moon nearly 30 years ago and became the third man to walk upon it, died Thursday evening after crashing his motorcycle near Ojai, Calif.

The former astronaut and Navy captain, who had survived more than 1,100 hours of often perilous space exploration, was 69.

Mr. Conrad was traveling from his home in Huntington Beach, south of Los Angeles, to Monterey along with his wife, Nancy, and several friends. About 80 miles into the journey, he apparently lost control on a bend of Highway 150 and was flung from his Harley-Davidson.

Mr. Conrad, who was wearing a helmet and obeying the 55 mile-an-hour speed limit, did not look badly hurt, but he complained of chest pains and difficulty breathing. Though doctors at Ojai Valley Community Hospital worked to save him, he died more than five hours later.

James Baroni, the deputy coroner of Ventura County, told The Associated Press that Mr. Conrad had suffered massive internal bleeding.

During his four space missions, Mr. Conrad logged 49 days, 3 hours and 37 minutes in space, a record at the time. He not only walked on the Moon but also set what was then a space endurance record of 28 days on the Skylab. And his associates say he did it without ever losing his sense of humor or his enthusiasm.

Three weeks ago, Mr. Conrad flew his private plane east to the Berkshires to be honored as an outstanding alumnus of Darrow School, a small preparatory school in New Lebanon, N.Y.

''He was incredibly energetic, not a man of 69 in his attitude about life or the space industry,'' Darrow's headmaster, Laurence R. Van Meter, recalled. ''There was nothing cynical about him at all.''

Charles Conrad Jr. was born on June 2, 1930, in the affluent Main Line suburbs of Philadelphia. His father, who served as a balloonist in World War I, was an investment broker. The future astronaut, who was always called Pete because his mother liked the name, was intrigued by flying and engines. As a child, he built model airplanes. As a teen-ager, he hung around local garages and airfields, neglecting his schoolwork. He swept up in a machine shop to finance flying lessons, and flew solo when he was 16.

To buck up his academic performance, Mr. Conrad was sent to Darrow School, where he became an excellent student, graduating with honors in 1949. Though he weighed barely 135 pounds and stood 5 feet 6 inches tall, Pete Conrad also played center on the football team so feistily that he was voted its captain. ''He was a very tough boy, and we won our share of games,'' said Charles Broadhead, the school's assistant headmaster at the time.

At Princeton, Mr. Conrad studied aeronautical engineering. Upon graduation in 1953 he joined the Navy, where he became an aviator, test pilot and flight instructor. In September 1962, he was selected as an astronaut.

In August 1965, he was a pilot on the Gemini 5 mission, which circled the Earth for eight days, a record at the time. In September 1966, he commanded the Gemini 11 mission, which set an altitude record of 850 miles and docked with another orbiting spacecraft.

In November 1969, Mr. Conrad commanded the Apollo 12 mission to the Moon, and repeated the lunar walk of Neil Armstrong and Edwin E. (Buzz) Aldrin Jr. Mr. Conrad spent seven hours and 45 minutes on the Moon's surface with Alan L. Bean, setting up a nuclear generator to power later experiments.

''Pete squeezed the most out of every opportunity to expand our knowledge and operating skills,'' Mr. Aldrin said yesterday.

Mr. Conrad went on, in May 1973, to set a record at the time of 28 days in space as commander of Skylab 2, the first manned space station. He considered that accomplishment as significant as his Moon landing.

After one solar-power wing blew off the orbiting Skylab and the other jammed, threatening to cut short the mission, Mr. Conrad and his crewmate Joseph P. Kerwin crawled out of the space station and for four hours floated on loose tethers, trying to pry the retracted panel free with a 25-foot pole. Even under such stress, Mr. Conrad's heart measured a relatively cool 100 beats a minute.

Mr. Conrad became as familiar to Americans for his gap-toothed grin and puckish sense of humor as for his courage in space. ''If you can't be good,'' he said, ''be colorful.''

When Mr. Armstrong first stepped on the lunar Ocean of Tranquility on July 20, 1969, he delivered his now-famous remark, ''That's one small step for a man, one giant leap for mankind.''

Four months later, Mr. Conrad, the shortest man in the corps of astronauts, made his walk on the Moon's cratered Ocean of Storms. ''Whoopee!'' he exclaimed when his foot touched the dry lunar dust. ''That may have been a small one for Neil, but that's a long one for me.''

When Mr. Conrad returned from Skylab with Mr. Kerwin and Comdr. Paul J. Weitz, President Richard M. Nixon presented the trio to the visiting Soviet leader Leonid I. Brezhnev. The astronauts went without the face masks they were supposed to wear to protect them from germs.

''If we catch a cold,'' Mr. Conrad told Nixon and Brezhnev, ''it will be an honor to catch a cold from you two gentlemen.''

After 20 years in the Navy, Mr. Conrad retired as a captain in 1973 to begin a business career, first as vice president for operations of the American Televison and Communications Corporation, a cable television company based in Denver. He moved to the Douglas Aircraft Company in 1978 as vice president for international sales and, later, marketing. When Douglas merged with McDonnell in 1986, he was named a vice president of the new McDonnell-Douglas Corporation, where he worked on a reusable launching vehicle, called the Delta Clipper, that NASA later turned down.

Though Mr. Conrad appeared in a tongue-in-cheek commercial for American Express credit cards, he was not caught up in his celebrity. ''My name may get me through some doors,'' The Orange County (Calif.) Register quoted him as saying. ''But I'd better know what I'm talking about in order to stay in the room.''

Mr. Conrad's fascination with space never waned. He started one aerospace company, Rocket Development, to build reusable spaceships, another, Universal Space Lines, to launch them, and a third, Universal Spacenet, to track them.

When a letter writer asked whether there was life in space, Mr. Conrad told The Los Angeles Times, he called it a definite possibility. ''After all, there's plenty of unearthly looking things moving around in my refrigerator,'' Mr. Conrad said, ''so there's always a chance of life springing up almost anywhere.''

He also talked about starting a space airline. ''I predict that people will be flying to space routinely for vacation,'' he told an audience in Washington two years ago.

Mr. Conrad's awards included the Congressional Space Medal of Honor, two Distinguished Service Medals from NASA, two Distinguished Service Medals from the Navy and two Distinguished Flying Crosses.

Mr. Conrad's first marriage, to Jane DuBose, ended in divorce. He is survived by his wife, Nancy Fortner Conrad, of Huntington Beach, and three sons, Peter, Thomas and Andrew. A fourth son, Christopher, died of bone cancer in 1990.

When Mr. Conrad returned to Darrow for his 50th class reunion last month, he wrote in its yearbook, ''I would not have gone to the Moon if I had not gone to Darrow.''

While at the reunion, he talked not only about his life in space but also about a vintage motorcycle he was restoring.

''It was clear,'' said Mr. Van Meter, the headmaster, ''that flying and motorcycles were, as they always had be for him, two major loves in his life.''

Charles Conrad (1930)