Rahman-Maskaev heavyweight date set for Aug.12

Heavyweight titlist Hasim Rahman will make his mandatory defense against Oleg Maskaev on Aug. 12 on HBO PPV at the Thomas & Mack Center in Las Vegas or Boardwalk Hall in Atlantic City, N.J., promoter Bob Arum told ESPN.com on Monday.

Arum was originally holding Aug. 12 for pound-for-pound king Floyd Mayweather Jr. to face welterweight titlist Antonio Margarito, but Mayweather declined, opening the pay-per-view date for Rahman-Maskaev.

That bout, a rematch of Maskaev's dramatic come-from-behind knockout victory in 1999, took on greater significance last weekend in the wake of Wladimir Klitschko's title-winning knockout victory against Chris Byrd in Germany.

The reason: Among the four recognized heavyweight title holders, Klitschko became the third from a former Soviet republic to beat an American to win a belt, leaving Rahman as the lone American heavyweight champion and Maskaev poised to give Eastern Europe a sweep of the titles in boxing's marquee division.

Arum said that he and Maskaev representative Dennis Rappaport are about $300,000 apart on making a deal. If they don't finalize terms, the WBC will hold a purse bid May 1 in Mexico City.

But Arum is confident they will make the deal.

"We're very close," Arum said. "It will take another day to work it out."

Arum said he is already making arrangements to announce the fight at a news conference in New York on May 10.

Arum said Margarito could wind up on the Rahman-Maskaev card in the co-feature.

"But it's tentative," Arum said. "If Mayweather decides to fight in September or October, and Margarito could still be a candidate, I want him to be flexible."

Another possibility for the undercard is junior bantamweight titlist Martin Castillo facing Jorge Arce, an interim flyweight title holder who is interested in moving up in weight.

Dan Rafael is the boxing writer for ESPN.com.