(Reuters) - The NHL and players union returned to the bargaining table for nearly eight hours on Tuesday in what is seen as a last ditch effort to hammer out a new labor deal and salvage a season.

Having already canceled hundreds of regular season games along with its showcase event the New Year's day Winter Classic, owners and players' representatives huddled at an undisclosed Manhattan location trying to lay framework for an agreement.

Following the marathon session both sides released statements that they would not comment on the negotiations that would resume on Wednesday.

"With meetings scheduled to resume Wednesday, the league will not characterize the substance or detail of the discussions until their conclusion," NHL deputy commissioner Bill Daly said in a statement.

The cancellation on Friday of the Winter Classic appears to have brought a sense of urgency to negotiations that have built a steady momentum.

Following a lengthy private meeting on Saturday between Daly and NHLPA special counsel Steve Fehr that set the stage for Tuesday's meeting, the big guns were again back at the table with league commissioner Gary Bettman and union executive director Donald Fehr joining the talks.

With the lockout at 52 days and counting, the two sides sat down for the first full bargaining session since October 18

"We're hopeful that we'll start bargaining and we'll continue bargaining until we find a way to make a deal," Donald Fehr told reporters before heading into the talks. "It's very good to be getting back to the table.

"We hope that this time it produces more progress than we've seen in the past and we can figure out a way to make an agreement and to get the game back on the ice as soon as possible."

With the chances for even a partial season slipping away talks have entered a critical stage if the NHL is to avoid losing an entire season for the second time in seven years.

The importance was not lost on the players with several, including Pittsburgh Penguins captain Sidney Crosby, arriving in New York in a show of support.

While no details were given it is likely the majority of Tuesday's session centered around the main obstacle to a new deal - how to divide $3.3 billion in hockey related revenue.

In its last offer, the NHL presented a six-year proposal that called for an equal split of hockey-related revenue. Under the old agreement players had received 57 percent of revenue.

The union offered three counter-proposals on October 18 that the league quickly shot down, saying later all failed to approach a 50-50 revenue split.

In an attempt to kick start negotiations, the league indicated it is willing to re-examine what has become known as the "make whole provision" that would honor all existing contracts even if the 50-50 split would come into immediate affect with the signing of an CBA.

(Editing by Greg Stutchbury)