(Reuters) - Talks between the NFL and its players' union have collapsed less than a month before the current collective bargaining agreement expires.

Thursday's scheduled meeting between league owners and representatives of the NFL Players Association (NFLPA) in Washington was canceled, a source told the NFL Network.

The owners walked away from the negotiating table on Wednesday when the players proposed to take an average of 50 percent of all revenue generated by the league, ESPN.com said, citing player sources.

No further meetings have been proposed, the sources said.

The current labor agreement expires on March 4 and the two sides appear far apart on an 18-game regular season, a rookie wage scale, drug testing and pensions for former players.

How to distribute the league's $9 billion in annual revenues also is a sticking point.

"We hope there's not a lockout, we just have to try and work this thing out at the bargaining table," Pittsburgh Steelers owner Art Rooney II said after Sunday's Super Bowl.

The two sides met Saturday in Dallas in talks NFL Commissioner Roger Goodell described as "beneficial."

Neither the NFL nor the players' union would comment on what prompted the cancellation of Thursday's meeting.

Gross NFL revenues could be cut by $120 million if no agreement is reached by early March, according to one estimate.

The figure could climb to $1 billion without a deal by the start of the NFL season in September.

Owners and the union reached the current agreement in 2006. It was scheduled to expire in 2012 but the owners in 2008 opted out effective this year.

The last NFL strike occurred in 1987. The players struck that season, demanding unfettered free agency.

After games were canceled for one week, the third week of the season, the NFL brought in replacement players who played for three weeks before the players' union ended its strike.

(Reporting by Gene Cherry in Salvo,