A ruling by a federal judge in Minneapolis could derail NFL owners' plans to lock out players at the end of the week.

U.S. District Judge David Doty ruled late Tuesday afternoon that a special master committed several errors in considering whether the NFL violated its agreements with the players union in compiling $4 billion in additional television revenue meant to help the league offset the expected lockout.

Saying that the league breached its agreement, Doty ordered that a hearing be held to determine damages paid to the NFL Players Association, as well as the possibility of keeping the NFL from using the $4 billion should a lockout occur. The hearing has not yet been scheduled.

Doty's decision comes as the NFL and the NFL Players Association are locked in a high-stakes dispute over how to divvy up $9 billion in total revenues for the country's most popular spectator sport.

While Doty didn't tell the league that it can't spend its $4 billion, he ruled that the league's contracts with DirectTV, CBS, Fox, NBC and ESPN breached its agreement with its players to use "good faith" in maximizing revenues to be shared by owners and players.

The hearing to determine damages will consider what the league will have to do to make things right. The special master had awarded nearly $7 million to the players. But, more important, his ruling allowed the owners to hold onto their $4 billion -- a move the players said funds a lockout. In a hearing last week, lawyers for the players union urged Doty to put that money in escrow to keep the league from using it to finance a lockout.

The question now is whether Doty's decision will affect ongoing contract negotiations between owners and players. NFL spokesman Greg Aiello said Doty's ruling doesn't sway talks either way.

"As we have frequently said, our clubs are prepared for any contingency, this decision included," he said. "Today's ruling will have no effect on our efforts to negotiate a new, balanced labor agreement."

It is unlikely that Doty's next decision -- on damages -- will come before a lockout could occur. The collective bargaining agreement between the league and the players union expires at 11 p.m. Thursday. If a new agreement is not reached by then, the owners will institute a lockout. The NFL Draft would go on as scheduled in late April, but other offseason activities would not, and free agency would be delayed until a new agreement is struck.

Doty first heard the case Thursday. He has presided over cases involving the NFL, the players union and their collective bargaining agreements for the past 19 years. The league has previously alleged that Doty has a pro-union bias and sought to have him removed from cases.

The union had asked Doty to issue an injunction, setting aside the ruling by special master Stephen Burbank, who refused earlier this month to put the $4 billion in 2011 television revenue into escrow while the league and its players negotiate. Doty's ruling Tuesday does overturn Burbank's decision but puts off the fate of the $4 billion until later.

The NFLPA wants the TV money made off-limits until any lockout ends and to have part of the money refunded if the season is cut short. Union attorneys say the NFL plans to use that money to finance the lockout, giving team owners revenue even if games are not played in 2011. Tom Heiden, a lawyer for the union, called it "a war chest" that would be used as leverage against the players.

James Walsh • 612-673-7428