Updated

The NFL and its players' union have finished meeting after spending about six hours at the office of a federal mediator for the second day in a row.

NFL Commissioner Roger Goodell declined to comment as he left the office of George Cohen, director of the Federal Mediation and Conciliation Service, a U.S. government agency.

Asked if he was sure he didn't want to say anything about the negotiations, Goodell replied: "That, I'm sure of," and got into a waiting car.

NFL Players Association executive director DeMaurice Smith also did not stop to take questions when he left.

New York Jets fullback Tony Richardson, Indianapolis Colts center Jeff Saturday and Pittsburgh Steelers quarterback Charlie Batch were among more than a dozen members of the union's negotiating team present Saturday.

"Nothing can be done without communicating," Saturday said.

The league and union met with Cohen for the first time Friday in a session that lasted about six hours. Cohen announced Thursday the groups agreed to the mediation, which is not binding but is meant as a way to initiate progress in the slow and sometimes contentious bargaining.

The plan calls for several days of negotiations with Cohen present.

The current collective bargaining agreement runs out at the end of the day March 3. The players believe that team owners are preparing to lock them out as soon as the following day, which could threaten the 2011 season.

News of the start of mediation could be 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 once last 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.

Cohen was involved in Major League Soccer's negotiations with its players' union last year, when a possible work stoppage was avoided.

He was the baseball players' association's lead lawyer in federal court in 1995, when the National Labor Relations Board obtained an injunction against owners from then-District Judge — and now Supreme Court Justice — Sonia Sotomayor that led players to end their 7½-month strike.

The FMCS was involved in negotiations during the 2004-05 NHL lockout, and a 2005 dispute between the U.S. Soccer Federation and its players.