Labor negotiations between the NHL and the locked-out players' association may resume Tuesday after a four-day break.

The location and the agenda have yet to be determined. The sides held two days of talks this week in New York without discussion of hockey-related revenue -- the core economic issue that has prevented the NHL regular season from starting on time.

"Nothing firm. There is a potential for Tuesday," NHL deputy commissioner Bill Daly said in an email to The Associated Press.

The 28-day lockout already has wiped out the entire preseason and the first three days of the regular season. The NHL announced last week that all games have been canceled through Oct. 24.

A deal will have to be struck soon to prevent more cancellations and provide an opportunity to make up the lost games and have a full 82-game season.

The sides finished two days of negotiations Thursday that again centered on secondary issues such as drug testing instead of focusing on how to divide up revenue.

The league and the union did little to close the gap, and the likelihood of any hockey being played in October is quickly fading. After five hours of talks at the league office on Wednesday, the sides got back together for nearly as long -- in two sessions -- on Thursday.

Daly estimated the NHL lost $100 million from the cancellation of the entire preseason and would be out another $140 million to $150 million with the regular-season losses.

The NHL still says it is waiting for a new proposal from the union, with the owners adamant players accept a significant drop from the 57 percent of revenue they received under the salary cap in the last contract. The players don't want what they consider more massive cuts at a time when the overall revenue pot reached record numbers ($3.3 billion) last year.