NFL Players Association executive director DeMaurice Smith didn’t stop for questions as he left the Washington office of the Federal Mediation and Conciliation Service, a U.S. government agency, shortly after 6 p.m. He and NFL Commissioner Roger Goodell arrived within minutes of each other, shortly before 10 a.m.

Sunday was the third consecutive — and, so far, longest — day of face-to-face communication after months of slow and sometimes contentious bargaining. The sides have met for a total of more than 20 hours since Friday in front of George Cohen, director of the Federal Mediation and Conciliation Service.

Because both sides agreed to Cohen’s request that they not comment publicly on these negotiations, it’s not clear what, if any, progress is being made.

"You know we’re not going to give you any information," NFL outside lawyer Bob Batterman said as he left with three league executives. "I can’t say anything, other than the fact that we are meeting."

Batterman, who represented the NHL when it lost its entire 2004-05 season to a lockout, then referred to Cohen as a "first-class mediator."

The NFL’s labor deal expires at the end of the day March 3. The union has said it believes team owners want to lock out the players as soon as the next day, which could threaten the 2011 season.

On his way into the talks Sunday morning, Jeff Pash, the NFL’s general counsel and lead labor negotiator said: "We are working hard, and we’re following the director’s playbook, and we’ll see what we come up with."

Lawyers Jeffrey Kessler and Richard Berthelsen, current players Tony Richardson of the New York Jets and Charlie Batch of the Pittsburgh Steelers, and former players Pete Kendall and Sean Morey were among those representing the union Sunday. They began arriving before 9 a.m.

"Conversation is good," Richardson said when he left.

The sides met for about six hours on both Friday and Saturday. Cohen announced Thursday the groups agreed to the mediation, which is not binding but is meant as a way to spur progress.

The plan calls for several days of negotiations with Cohen present. The mediation could be seen as a positive sign after several months of infrequent negotiations — and frequent rhetoric, including charges from each side that the other was hoping for a work stoppage.

The league and union went more than two months without any formal bargaining until Feb. 5, the day before the Super Bowl. The sides met again the next week but called off a second meeting that had been scheduled for the following day.

The most recent CBA was signed in 2006, but owners exercised an opt-out clause in 2008.

The biggest issue separating the sides is how to divide about $9 billion in annual revenues. Among the other significant points in negotiations: the owners’ push to expand the regular season from 16 games to 18 while reducing the preseason by two games; a rookie wage scale; and benefits for retired players.

No team owners have been seen at the mediated sessions, but they’re surely keeping up with what’s happening — and at least one indicated optimism about the 2011 season in a roundabout way.

Indianapolis Colts owner Jim Irsay tweeted Sunday: "T Minus 351 days 2 Sup Bowl kickoff in Indy…early predictions 4 participating teams???"