NFL labor negotiations took yet another surprising turn late Sunday when the league and union agreed to postpone free agency another 72 hours, giving the sides more time to try to reach agreement on a contract extension.

NFL spokesman Greg Aiello said the delay would give owners a chance to consider the union's latest proposal during a meeting Tuesday in Dallas.

Talks broke off earlier in the day, leaving dozens of veterans in danger of becoming salary-cap casualties before free agency was supposed to begin Monday at a minute after midnight.

The breakdown in talks was typical of the topsy-turvy negotiations, so far: Just when things seemed darkest, they got back on track; and when it appeared a deal could be struck, talks fell apart.

The union broke off Sunday's session.

"The talks ended after the NFL gave us a proposal which provided a percentage of revenues for the players which would be less than they received over the last 12 years," said Gene Upshaw, executive director of the NFL Players Association. "After suggesting we extend the waiver deadline from six o'clock to 10 this evening, they gave us a new proposal which was worse than their prior offer. Quite naturally, we rejected that proposal and saw no need to continue meeting."

But Harold Henderson, the NFL's executive vice president for labor relations, said the union rejected a proposal that would have added $577 million for players in 2006 compared to 2005 and $1.5 billion in the six years of the extension. "It's an unfortunate situation for the players, the fans and the league," Henderson said.

A mere four hours later, things were fluid again.

After a conference call between owners and league officials, including commissioner Paul Tagliabue, the league announced yet another extension - the second 72-hour respite in free agency, which originally was to start Friday.

"The NFL and the NFL Players Association have agreed to extend the start of the 2006 league year for 72 hours - until 12:01 a.m., EST, Thursday, March 9 - in order to allow the NFL clubs to meet in Dallas on Tuesday to consider the NFL Players Association's offer," the NFL said.

Shortly afterward, Upshaw said:

"The NFL negotiators called us tonight after our negotiations broke off to indicate that they will take our complete package to the owners for an approval vote on Tuesday. We have therefore agreed to extend the free agency deadline until midnight Wednesday in order to provide time for that vote to be accomplished. It was the NFL's previous rejection of our proposal earlier this evening that caused the talks to break down."

The deadline for teams to be under the salary cap also was pushed back. Though cuts had already started, the cap extension changed things.

The Oakland Raiders thought they would be forced to let quarterback Kerry Collins go, saving $9.2 million in cap space, however, the delay gave them a reprieve. Center Kevin Mawae was cut by the New York Jets, although he probably would have been gone anyway because he is 35 and missed the final 10 games of last season with a triceps injury.

The Washington Redskins, the team believed to be in the most cap trouble, said they had worked out an agreement to make linebacker LaVar Arrington, a three-time Pro Bowl player, a free agent. An official with knowledge of the transaction told The Associated Press that Arrington had agreed to a buyout that would save the team cap space it wouldn't have had if it had cut him.

Other big names also could go if teams try to squeeze under a salary cap of $94.5 million. If a deal is reached, the cap could go as much as 10 million higher - in other words, allowing teams to keep some of the players.

Amid all the labor back-and-forth came news that running back Shaun Alexander was staying put: The league's MVP agreed to return to the NFC champion Seattle Seahawks for $62 million over eight years, with $15.1 guaranteed, according to his agent, Jim Steiner.

These negotiations were by far the most difficult since the NFL and the union first agreed to free agency and a salary cap in 1992, ending years of labor unrest that included player strikes in 1982 and 1987. The contract has been extended several times since then, most of the time with ease.

Even now, the contract doesn't expire until 2008, but this would be the last year of a salary cap - 2007 would be uncapped, which could lead to wild spending by some teams and little by others, creating a haves/have not situation similar to the one in baseball.

One reason these talks were more difficult is that the players asked for a change in the system.

Until now, they received their money primarily from television and ticket revenues. This time, they requested their share from all team revenues, including outside money generated by everything from parking fees to stadium naming rights.

That led to difficult negotiations, in part, because the teams themselves are having their own dispute over that money because of the disparity in outside income made by low-revenue teams like Buffalo and Indianapolis and high-revenue teams like Dallas, Washington, New England and Philadelphia. Union leaders had suggested that it would be hard to reach agreement on a labor contract until the owners settled their own differences.

Both sides seemed ready to compromise on Sunday, largely because of the pressure of impending free agency, which was supposed to begin last Friday. However, it was put off for three days so the sides could keep talking.

Negotiations appeared to be at a standstill last Thursday, when the owners took just 57 minutes to reject the union's last offer. But seven hours later, the sides reversed course and started talking again.

Upshaw said he still thinks revenue sharing is the key, although Henderson said it was never discussed. Upshaw also said the players would do as well or better sticking with the current agreement.

"Under our previous cap agreement, we got just less than 60 percent of all of the revenues. The NFL now wants us to cut that percentage to less than 57 percent. Given the enormous revenue growth the NFL is experiencing, I am not about to give back gains which we have made in the past. It is clear to me that we will do much better under our current CBA in 2006 and particularly in 2007, the uncapped year," Upshaw said.