Jeris White's four-week contract holdout ended yesterday when the veteran cornerback approved a three-year agreement with the Redskins.

White's decision ended a 48-hour stretch that saw the Redskins obtain fullback Wilbur Jackson in a trade, end one contract holdout and find new hope that another contract dispute, involving John Riggins, might be resolved soon.

"This is the most optimistic I've felt in a while," General Manager Bobby Beathard said yesterday. "Spirits are brighter around here. It was good to get Wilbur and now to have Jeris ready to come to camp is great.

"I also think John is ready to come back. I hope so. We want him and we've let him know that. It wouldn't surprise me if he comes back this week. It seems as if he has laid the foundation for a return."

On Friday, Riggins dropped his demands for contract renegotiation. Although he claimed chances of his returning this season are remote, he left the door wide open for a change of mind if he suddenly "rediscovered" his zest for football.

"We aren't too proud to take him back," Beathard said. "Although we are convinced our stand against renegotiation is correct, that doesn't mean we have something against him. We'd be stupid to say, 'The hell with John'."

White, who was obtained from Tampa Bay in a trade for receiver Danny Buggs and a fourth-round draft choice, is scheduled to arrive at Redskin Park Monday morning to sign his contract. Although Beathard would not comment on terms, the pact is believed to be in the $115,000-a-year range.

The club will ask the league for a two-week exemption so that White will not be counted immediately on the active roster.That will give the Redskins time to evaluate him and decide on his role. Beathard was certain the exemption woud be granted, but if not, he would have to cut a player to make room for White.

White's presence will create a dilemma for Coach Jack Pardee. When the trade was made, he was projected as a possible starter ahead of Joe Lavender. But at this late date in camp, he most likely will be used at first in a specialist role, particularly as a force man on running plays.

Backup cornerback Ray Waddy has had an excellent training camp, but the team kept only three corners last year and it might be difficult to exceed that total this season because of roster limitations.

Beathard had been pessimistic the last two weeks that White, who was on the option year of his Tampa Bay contract, would ever come to terms with the Redskins. But White's agent, Howard Slusher, started negotiations with a surprise telephone call Thursday to the Washington general manager.

"I was upset that we hadn't talked for a long time and that he hadn't called me back," Beathard daid. "But Howard said he thought we were going to call him. Anyway, he was more reasonable in his demands this time.We made a small compromise but basically it's the contract we've been offering."

Slusher and Beathard reached agreement Friday, but White did not approve the contracat officially until yesterday. He had been holding out for a salary in the $140,000 range, but Washington refused to go that high.

"I don't foresee any problems with Jeris fitting in despite the holdout." Beathard said. "He is a nice person and he won't come in here causing any problems. But I still think the holdout was unnecessary. It will certainly hurt his development early in the season."

White, a seven-year man from Hawaii, was a second-round 1974 Miami draft pick. He started the last four years for Tampa Bay, which had the league's No. 1 defense last year. He averaged more than 80 tackles a season during his tenure with the Bucs.