Heavyweight contender DaVarryl Williamson is to to challenge IBF champion Chris Byrd.

Byrd signed for the bout on Friday and Showtime and promoter Don King are working on staging the fight in Reno, Nevada on October 1. If the fight is confirmed for the aforementioned date then it will form a three fight championship card to go head to head with HBO, who broadcast the rubber match between Antonio Tarver and Roy Jones Jr.

Showtime also is airing heavyweight James Toney vs. Dominick Guinn and bantamweight champ Rafael Marquez vs. Silence Mabuza.

If Byrd-Williamson lands on the Showtime date, it would serve as a prelude to Byrd facing fellow Michigan native Toney in a significant title defense early next year.

Byrd signed the bout agreement to face Williamson, his former sparring partner, reluctantly because although his minimum purse under his contract with King calls for $2.5 million, he's fighting Williamson for $425,425.

That's because his minimum doesn't come into play if a fight is won at a purse bid. King was the only bidder, winning it for $500,500. Williamson gets the remaining $75,075.