WASHINGTON  The National Football League, which last year had revenues of more than $9 billion as America’s most popular sport, was plunged into deep uncertainty Friday when negotiations between owners and players for a new contract broke off. At 12:01 a.m. Saturday, the owners locked out the players to create the game’s first work stoppage since 1987 and imperil the 2011 regular season.

After a final day of negotiations, the players union formally dissolved itself, a process known as decertification. Such a move is highly unusual, but it allowed players to seek an injunction in federal court to prevent the league from implementing a lockout and to sue the N.F.L. on antitrust grounds.

Among the 10 named plaintiffs in the 52-page antitrust suit filed in United States District Court in Minneapolis are some of the game’s most famous players, including quarterbacks Tom Brady, Peyton Manning and Drew Brees. Because the plaintiffs are listed alphabetically, the lawsuit will technically be referred to as Brady v. N.F.L.

The bitter rupture was the culmination of months of largely fruitless negotiation, and it essentially froze much of the business of the league in place. Until the court takes up the request for an injunction  union officials said they did not expect an initial decision for three or four weeks  players cannot sign with teams, trades are barred, and there can be no contact between the league’s coaches and its players.