NEW YORK (AP)—Mike Tyson will defend his undisputed heavyweight title against Michael Spinks in June, Spinks’ adviser said Wednesday.

“We’ve agreed verbally,” Butch Lewis said after months of often-bitter negotiations. “We’re now having the contract reduced to writing” and a signing is expected early next week.

No site or date has been picked, Lewis said. The bout between the unbeaten fighters will be shown on closed-circuit television.

“This is the only fight in boxing,” Lewis said. “This is the one everyone wanted to see.”

Lewis said the fight was expected to gross between $60 million and $70 million and make a net profit of nearly $40 million.

Spinks will fight for a flat sum plus incentives. His guarantee reportedly is in the neighborhood of $12.5 to 13.5 million.

Everything else will go to Tyson, with promoter Don King being paid out of the champion’s revenues. Tyson is expected to earn at least $17 million.

“If the thing hits a home run and the net is close to $40 million, Tyson can touch $20 million,” said Shelly Finkel, who has the closed-circuit and pay-per-view television rights for the bout.

Negotiations with Lewis were conducted by Finkel, who was serving as a go-between for Tyson’s co-managers Jimmy Jacobs and Bill Cayton. Milt Trotsky handled negotiations for Spinks’ camp.

Cayton said he and Jacobs would not deal with Lewis personally after Lewis walked out of a negotiating session Jan. 23, the day after Tyson knocked out Larry Holmes in Atlantic City, N.J.

The Tyson-Spinks fight plan assumes that Tyson will successfully defend his title in his next bout, on March 21 against Tony Tubbs in Tokyo.

Spinks, the former light heavyweight champion, was stripped of the International Boxing Federation heavyweight title when he dropped out the HBO unification tournament in order to fight Gerry Cooney last year.

Tyson, 21, has a record of 33 wins, including 29 knockouts. Spinks has 31 victories with 21 knockouts.

Atlantic City and Las Vegas, Nev., were thought to be the leading contenders as the site.