SALVO, North Carolina, April 7 (Reuters Legal) - A federal judge said she would need around two weeks to rule on an injunction brought by NFL players seeking to end a lockout, and urged the football players and owners to resume talks to end the labor dispute themselves.

"It seems to me that both sides are at risk." Judge Susan Richard Nelson said after a full day of legal arguments in Minnesota on Wednesday.

"It will probably take me a couple of weeks to do a fair job to both sides," she said.

The players had asked for an immediate ruling, saying the lockout amounted to an antitrust violation brought about by the illegal collusion of team owners.

But league attorney David Boies questioned whether the court had jurisdiction in the case, saying the National Labor Relations Board should first rule on an owners' complaint against the players' union.

Both sides have indicated they would lodge an appeal if they lost the decision on the injunction, setting the stage for a long and costly legal battle.

The NFL ordered the lockout after talks between the league and the players' union collapsed, plunging America's most popular professional sport into its first work stoppage in almost a quarter of a century.

The league and the players were unable to reach an agreement over a range of issues, including how to divide up more than $9 billion in annual revenues.

Under the expired agreement signed in 2006, owners received a guaranteed $1 billion of the annual revenue while the rest was split, with players getting around 60 percent and the owners 40 percent.

The league and owners wanted to increase their automatic cut, arguing that operational costs had risen since the last deal was struck, but the players wanted to maintain the status quo.

With the 2011 season not due to kick off until September, there is still time for the parties to avoid the massive revenue loss that would occur if the season is delayed or cancelled.

Both sides in the dispute have been criticized for demanding huge sums of money at a time when many families are struggling to make ends meet. President Barack Obama said he would not get involved in the matter, which he characterized as a battle between billionaires and millionaires.

The case is Tom Brady et al v. National Football League, U.S. District Court for the District of Minnesota, No. 11-cv-639.

For the players: Barbara Berens and Justi Rae Miller of Berens & Miller; Timothy Thornton of Briggs and Morgan; James Quinn and Bruce Meyer of Weil, Gotshal & Manges; Jeffrey Kessler, David Feher and David Greenspan of Dewey & LeBoeuf.

For the NFL: Daniel Connolly and Aaron Van Oort of Faegre & Benson; David Boies and William Isaacson of Boies, Schiller & Flexner; Gregg Levy and Benjamin Block of Covington & Burling.

(Reporting by Gene Cherry of Reuters; Additional reporting by Jeff Roberts of Reuters Legal)