alph Sampson ended the suspense this evening by announcing he will remain at the University of Virginia for his fourth and final year, and forgo the fortune to be made in professional basketball until 1983, when his class graduates.

Sampson said that, at one point, he wanted to join the National Basketball Association, but decided this morning to stay in college.

"I did a lot of soul searching, but I decided to stay for my fourth year," he said in a 20-minute, videotaped presentation. "It got down to what I wanted to do, and that was to come back for another year."

Had the 7-foot-4 Sampson decided to skip his final year of college eligibility, he would have been the first player drafted June 29 by the Los Angeles Lakers or the San Diego Clippers and probably would have commanded at least $1 million for his first year's salary.

But Sampson, college basketball's player of the year the last two seasons, said he wants another chance to win the NCAA championship, and that the money still will be available next year.

"They said I'd lose my bargaining power, but I don't really think you lose it because you have to bargain eventually anyway to get the money you want," he said.

Sampson indicated he would have left Virginia had the Lakers acquired the Clippers' pick before today. "I thought real hard about turning pro . . . if the pick had gone a certain way," he said.

The Lakers had offered as much as $6 million, plus other considerations, for that selection, which would have assured them of getting the player of their choice in the draft. But the Clippers refused. Sampson said a last-minute deal by the Lakers would not have changed his mind.

In San Antonio, where his team was playing the Spurs in the NBA Western Conference championship series, Lakers owner Jerry Buss said, "It's disappointing. He's one of the premiere players ever. I think the fans in Los Angeles deserve this kind of player . . . We still have the premiere center in the league and we expect him to play for a couple of more years. We just felt that Ralph Sampson being coached by Kareem would be good for both Ralph and the Lakers."

Sampson turned down an offer of $400,000 from the Boston Celtics after his freshman year, and $800,000 from Detroit and Dallas after his sophomore year.

With Sampson deciding to stay in school, the first player drafted could be North Carolina's James Worthy, who will announce Saturday whether he will be available. Should Worthy stay in school, two other underclassmen, De Paul's Terry Cummings and Georgia's Dominique Wilkins, probably will be the first two drafted.

Others who have said they want to pass up their senior seasons are Texas center LaSalle Thompson, San Francisco's all-America guard Quintin Dailey, Boston College guard John Bagley, Ohio State forward Clark Kellogg, Wichita State forward Cliff Levingston and Houston guard Rob Williams.

Virginia has compiled a 83-18 record with Sampson, who has averaged 16 points and 11 rebounds in three seasons.

Sampson didn't tell Coach Terry Holland or teammates his decision until 4 p.m. today. Holland, in fact, had told a Virginia official only 15 minutes before that it didn't look too good.

But Sampson called a team meeting at his apartment in Holland's basement to say he was staying.

"We sat around Ralph's place for about 25 minutes, trying to act like nothing important was about to happen," said guard Rick Carlisle. "I went upstairs to play the piano because I couldn't take (the suspense). When he told us, there were a couple of mild cheers. Ralph looked comfortable."

Holland, of course, was elated with Sampson's decision. "Having gone through it three different ways, I think Ralph is an expert at this," said Holland. "I think it's important that he weighed all the information and felt good about his decision.

"I think," said Holland, "we have, certainly, one of the finest teams in the nation right now."