New York ? The start of the NBA season was thrown into doubt Tuesday after players and owners remained divided over the salary cap structure at a key labor meeting.

Tentative plans to talk again today were scrapped, and no further sessions were scheduled.

Union executive director Billy Hunter said players were prepared to make a “significant” financial move, but found owners unwilling to budge off their positions. Commissioner David Stern and Deputy Commissioner Adam Silver countered that the union insisted the current cap remain exactly as is before they would agree to any further discussions.

A sign of how the day went: Owners spent the majority of about five hours of behind closed doors caucusing among themselves.

Union president Derek Fisher of the Lakers said he will tell players that “the way it looks right now we may not start on time.”

Fisher added that “we can’t find a place with the league and our owners where we can reach a deal sooner rather than later.”

After three meetings among small groups in the last two weeks, full bargaining committees returned to the table Tuesday. They could have also met today, but Stern said it was best the two sides step away and meet with their own membership groups on Thursday.

Though owners are seeking an overhaul of the league’s financial system after saying they lost $300 million last season, the salary cap appears to have emerged as the biggest obstacle to a new deal.

The current soft cap system allows teams to exceed the ceiling through the use of various exceptions if they are willing to pay a luxury tax, giving big-market teams such as the Lakers — who can take on added payroll — an advantage over the little guys.

But Hunter said a hard cap is “highly untenable,” referring to it as a “blood issue” to the players. Stern said players wouldn’t negotiate without first getting a guarantee from the league that it would concede on the salary cap.

“All of the owners were completely unified in the view that we needed a system that … allowed 30 teams to compete,” Stern said.