A federal judge ruled Tuesday that the N.F.L. acted against players’ interests when it failed to maximize revenue from networks when it renegotiated its television deals.

“The record shows that the N.F.L. undertook contract renegotiations to advance its own interests and harm the interests of the players,” United States District Court Judge David S. Doty said.

Doty’s decision is critical to the players union’s hope of forcing the league to put $4 billion in 2011 television network revenue in escrow if there is a lockout. The collective-bargaining agreement between the league and the union expires at midnight Thursday.

In its statement, the union said: “This ruling means there is irrefutable evidence that owners had a premeditated plan to lock out players and fans for more than two years. The players want to play football. That is the only goal we are focused on.”