Winky Wright has defeated two of the three fighters Oscar De La Hoya could not, taking decisions over Shane Mosley twice and Felix Trinidad.
On July 21, he'll try to add Bernard Hopkins.
Wright's adviser and attorney, Jim Wilkes, said the St. Petersburg boxer and Hopkins, two of the top pound-for-pound and defensive fighters in the world, have agreed to meet at 170 pounds.
"It's going to be interesting," Wilkes said. "When Winky wins, he will have beaten all the guys that beat Oscar. Maybe that will convince Oscar he should fight Winky later this year."
Although an official announcement has not been scheduled, Wilkes said the deal was completed, for the most part, Thursday. Contracts haven't been signed, and the site - most likely Madison Square Garden New York or Las Vegas - hasn't been chosen, but Wilkes said those are formalities.
"This isn't an agreed in principle thing. It's agreed in details," he said.
The HBO broadcast will likely be pay-per-view and give Wright, 35, the biggest payday of his 16-year career. Financial details were not revealed.
Hopkins, 42, one of the middleweight division's all-time greats and Ring Magazine light heavyweight champion, said he was retiring after beating Tampa's Antonio Tarver last summer. But he announced a comeback in December, flirted with going after the heavyweight title or a rematch with Roy Jones and settled on a fight with Wright.
Hopkins (47-4-1, 32 knockouts) is aligned with Golden Boy Promotions as a president of its East Coast division and had a hand in co-promoting Wright's most recent fight, a decision over Ike Quartey at the St. Pete Times Forum in Tampa.
Wright (51-3-1) has never fought above 160 pounds, which is why the bout has been agreed to so far in advance. Wilkes said the 5-foot-101/2 Wright will undergo two months of weight training.