BUFFALO, N.Y. -- Mark Hamister prepared to submit a revised proposal to Adelphia Communications Thursday, hopeful he can meet next week's NHL deadline to complete his conditional purchase of the bankrupt Buffalo Sabres.

Reaching a deal with Adelphia, one of the nation's largest cable television companies, is critical to Hamister and majority partner Todd Berman's bid to sign an asset purchase agreement for the Sabres.

The prospective owners, who have been granted four deadline extensions by the NHL this past month, now have until Monday to complete their agreement or risk losing their exclusive rights to purchase the franchise, potentially jeopardizing the team's future in Buffalo beyond this season.

"We're sending a revised document to them today and we'll see how they react," Hamister said. "We'll make as much progress as we can."

Adelphia, which filed for Chapter 11 bankruptcy protection last summer, is the Sabres largest creditor, owed between $130 million and $160 million in money former Sabres owner and former Adelphia CEO John Rigas used to purchase and operate the team in the 1990s.

Adelphia turned down the prospective owners' initial offer last week, responding with about 40 proposed revisions.

The company has since significantly scaled back its list of demands in hopes of moving the process forward, and doesn't consider any of the outstanding issues deal-breakers.

"We continue to support this bid as does the NHL and continue to work with both parties to reach a successful conclusion which would keep the Sabres in Buffalo under Hamister's ownership," Adelphia spokesman Eric Andrus said.

Adelphia doesn't have many other options but to continue negotiating with Hamister and Berman.

The prospective owners have offered Adelphia $33 million in guaranteed money, $13 million more than what Rochester billionaire B. Thomas Golisano was offering before his Sabres bid was rejected by the NHL last November.

The main sticking point in Adelphia's negotiations with Hamister-Berman is believed to focus on the prospective owners' request that $7 million of their offer to be used to pay Sabres' unsecured creditors.

NHL officials, preparing for this weekend's All-Star Game festivities in southern Florida, were unavailable for comment.

Last week, NHL vice president Bill Daly said "Adelphia Communications has been exceedingly cooperative in addressing the issues of this extremely complicated matter and in working with Hamister and Berman in the attempt to bring their bid to a successful conclusion."

It's unclear whether the NHL would be willing to grant what would be a fifth deadline extension to the prospective owners.

Previously, NHL commissioner Gary Bettman has said that the Sabres could fold or move after this season should Hamister and Berman fail to complete their purchase.

Meeting Monday's deadline would be only one step in a complex sale process.

The prospective owners would also have to be approved by both an Adelphia bankruptcy court judge in Manhattan and the Sabres bankruptcy court judge in Buffalo.

Hamister and Berman also insist their purchase is contingent on them receiving a public assistance package initially estimated to be worth more than $40 million.

Hamister said that he's since revised part of the bid, asking for between $2 million and $4 million less in government assistance, money which he and Berman are prepared make up on their own.