Talks between NBA players and owners broke down on Thursday, raising the prospect that more games will be cancelled after the two sides failed to resolve financial differences.
Thirty hours of negotiations over the past three days, under the eye of federal mediator George Cohen, had raised some hopes that the parties had made progress towards agreement over two key issues: the division of revenues and a salary cap system.
"Ultimately we were unable to bridge the gap that separates the two parties," NBA Deputy Commissioner Adam Silver said. "We understand the ramifications of where we are. We're saddened on behalf of the game."
NBA commissioner David Stern - who missed Thursday's meetings with the flu - has already wiped out the scheduled first two weeks of the campaign, 100 games from November 1-14.
Union president Derek Fisher said the players are aware of the seriousness of the situation.
"This is not in any way about ego," Fisher said. "There are a lot of people's livelihoods at stake separate from us."
Stern had already indicated that if some sort of deal could not be reached this week, games in December could be in jeopardy.
"Hopefully, we can get back to the table but certainly a tough day, a very tough day," the NBA's labor relations committee chair Peter Holt said.
Owners locked out players on July 1, after the expiration of the prior collective contract, but the two sides have been unable to reach terms on a new agreement.
One stalemate is over how to divide some $4 billion in revenues.
Under the last contract, players were guaranteed 57 percent of basketball-related income, and each side had proposed receiving 53 percent of basketball-related income in a new deal.
Silver said the league formally proposed a 50-50 split on Wednesday, but that was insufficient for the players union.
Cohen said in a statement that the two sides remained separated on "core issues" and that he and fellow mediator Scot Beckenbaugh felt "that no useful purpose would be served by requesting the parties to continue the mediation process at this time."