Washington ? Unable to decide how to divvy up $9 billion a year, NFL owners and players put the country’s most popular sport in limbo Friday by breaking off labor negotiations hours before their contract expired. The union decertified; the league imposed a lockout.

Ten players, including MVP quarterbacks Tom Brady and Peyton Manning, sued the owners in federal court in Minneapolis. Then, at midnight, the owners locked out the players, two people with knowledge of the league’s decision told the Associated Press — signaling the NFL’s first work stoppage since 1987.

One of the people told the AP that the league informed all 32 teams and the union about the move shortly before 12 a.m.

Both spoke on condition of anonymity because they were not authorized to release the information.

Despite two extensions to the collective bargaining agreement during 16 days of talks overseen by a federal mediator — and previous months of stop-and-start negotiating — the sides could not agree on a new deal. Now they will be adversaries in court: The players already requested an injunction to block a lockout, even before one was in place.

As was clear all along, the dispute came down to money. In the end, it appeared the sides were about $185 million apart on how much owners should get up front each season for certain operating expenses before splitting the rest of the revenues with players — a far cry from the $1 billion that separated the sides for so long.

But the NFL Players Association refused to budge any further without getting detailed financial information for each team.

“I would dare any one of you to pull out any economic indicator that would suggest that the National Football League is falling on hard times,” NFLPA executive director DeMaurice Smith said. “The last 14 days, the National Football League has said, ‘Trust us.’ But when it came time for verification, they told us it was none of our business.”

By dissolving and announcing it no longer represents the players in collective bargaining, the union cleared the way for class-action lawsuits against the NFL, which opted out of the CBA in 2008. The antitrust suit — forever to be known as Brady et al vs. National Football League et al — attacked the league’s policies on the draft, salary cap and free-agent restrictions such as franchise-player tags.

Invoking the Sherman Act, a federal antitrust statute from 1890 that limits monopolies and restrictions on commerce, the players are seeking triple the amount of damages they’ve incurred. That means the stakes here could be in the hundreds of millions.

It could take a month for there to be a ruling on the union’s injunction request, and antitrust judgments should take longer.