By Dan Rafael ESPN.com Although HBO announced the long discussed Sergio Martinez-Paul Williams rematch during Saturday night's "Boxing After Dark" telecast, the fight remains unsigned and no venue has been determined, Lou DiBella, Martinez's promoter, told ESPN.com. DiBella said he felt the fight would get done and he has Boardwalk Hall in Atlantic City, N.J., on hold for the Nov. 20 rematch, although it's not a lock as the host. "I've felt we have had a deal for a month, but for whatever reason the Williams side has not signed off yet," DiBella said. "I believe they will. More important, HBO believes they will, so they announced the fight. I was surprised when I saw it." Martinez, the middleweight champion, lost a tight decision to Williams in a December fight-of-the-year candidate. In his next fight, Martinez outpointed Kelly Pavlik to win the title.