WASHINGTON -- NFL Commissioner Roger Goodell and all 10 members of the owners' labor committee have left a mediation session with the players' union after about four hours of talks.

The NFL contingent got into a fleet of a half-dozen black SUVs to drive to a hotel about 25 miles away in Chantilly, Va., where the 32 team owners are gathering.

About 20 minutes later, the NFL Players Association negotiating group left on foot, walking in the direction of the union's headquarters, a couple of blocks away from the Federal Mediation and Conciliation Service. Union president Kevin Mawae and New Orleans Saints quarterback Drew Brees, a member of the NFLPA executive committee, attended the mediation for the first time.

The CBA runs out at midnight Eastern time as Thursday becomes Friday, and among the possibilities are that the owners lock out the players or that the union decertifies. Whatever happens this week could cause the country's most popular sport to lose regular-season games to a work stoppage for the first time since 1987. Or, perhaps, everything could be resolved by management and labor in an industry with revenues topping $9 billion annually.

"So far, obviously, we haven't been successful," Carolina Panthers owner Jerry Richardson said on his way into the mediation session shortly before 10 a.m., "but we're optimistic in due time we will."

Added Richardson: "We have a league meeting, and we decided it would be a good idea for our full committee to meet with the mediation process this morning. Our objective, of course, is to negotiate a fair agreement for the players and the teams."

NFL general counsel and lead labor negotiator Jeff Pash reiterated that it is possible that the league and union could agree to extend the deadline for arriving at a new CBA.

"We have to see where we are. We've said that's an option. We're not taking anything off the table," Pash said.

Labor committee members joining Richardson on Wednesday at the talks were Jerry Jones of the Dallas Cowboys, Bob Kraft of the New England Patriots, Art Rooney of the Pittsburgh Steelers, John Mara of the New York Giants, Mike Brown of Cincinnati Bengals, Clark Hunt of the Kansas City Chiefs, Dean Spanos of the San Diego Chargers, Mark Murphy of the Green Bay Packers, and Pat Bowlen of the Denver Broncos.

Until Mara attended Tuesday's talks, no team owners had participated in the mediation sessions that began Feb. 18.

The group of owners walked in with NFL Commissioner Roger Goodell on Wednesday.

"We're looking forward to the conversations, and this is in keeping with what we've been telling you -- that we take this process very seriously," Pash said. "We're committed to negotiating an agreement and we're eager to have the discussion start this morning."

Asked whether mediation would end Wednesday, Pash said: "Certainly not. Negotiations don't end today. You keep negotiating until you reach an agreement, and I think the mediators, if they're willing, can continue to be a constructive part of that process."

Brees is a member of the NFL Players Association executive committee, and entered the building with other members of the union's negotiating team, including NFLPA head DeMaurice Smith. Wednesday was Brees' first day at the mediation; he's the 10th member of the union's executive committee to attend.

Because mediator George Cohen told both sides to stay silent publicly about the current talks, no one has revealed any specifics about what progress might have been made.

The biggest sticking point all along has been how to divide the league's revenues, including what cut team owners should get up front to help cover certain costs, such as stadium construction. Under the old deal, owners got $1 billion off the top. They entered these negotiations seeking to double that.

Among the other significant topics: a rookie wage scale; the owners' push to expand the regular season from 16 games to 18 while reducing the preseason by two games; and benefits for retired players.

While the NFL and union met for six hours Tuesday, that day's most significant development might very well have come in Minneapolis, where a judged sided with the union in a ruling about TV contract money.

U.S. District Court judge David Doty overruled a special master's Feb. 1 decision to reject the NFLPA's request that $4 billion in 2011 payments from networks to the league be placed in escrow if there is a lockout.

"The record shows that the NFL undertook contract renegotiations to advance its own interests and harm the interests of the players," Doty wrote in his ruling.

Doty, who has jurisdiction over NFL labor matters, said there will be a hearing to determine what should happen to that money. The date of the hearing wasn't announced immediately.

The NFL played down the importance of Doty's decision. The union issued a statement calling it "irrefutable evidence that owners had a premeditated plan to lock out players and fans for more than two years."

The union accused the NFL of structuring TV contracts agreed to in 2009 and 2010 so owners would be guaranteed money even if there were a work stoppage in 2011 -- while not getting the most revenue possible in other seasons, when income would need to be shared with players. The union argued this violated an agreement between the sides that says the NFL must make good-faith efforts to maximize revenue for players. The NFLPA also said any work stoppage clauses in TV deals guaranteed "war chest" income for the NFL, giving it an unfair advantage in labor talks.

Pash said Wednesday that Doty's ruling "doesn't change the dynamic for us at all. We've been very clear that the television money was a loan. It's not a payment. It's not anything we were counting on. The decision was, frankly, not unexpected. And so it doesn't alter our planning one iota."