NEW YORK (AP) — NFL owners and players’ association leaders met for more than 12 hours Thursday, failing to reach a deal to end the league’s months-long lockout but returning to try again in the morning.

“We still have a lot of work to do,” NFLPA chief DeMaurice Smith said as he emerged from the Manhattan law office where talks went deep into the evening. “We spent all day working hard for a deal that is fair and in keeping with what the players deserve.”

While Smith stressed the gaps in the deal, players involved in a lawsuit against the league had a conference call during which it became clear the two sides were close to agreement on the rules for free agency, a person with knowledge of the situation told The Associated Press.

The person, who spoke on condition of anonymity because details of the labor talks are not being announced publicly, said even with the progress in the negotiations another long day of talks was expected Friday.

NFL Commissioner Roger Goodell led the league’s group, which also included owners Robert Kraft of the Patriots, John Mara of the New York Giants and Jerry Jones of the Dallas Cowboys. NFLPA president Kevin Mawae was among the players’ representatives.

U.S. Magistrate Judge Arthur J. Boylan, who has served as a mediator between the two sides, also was involved. He is scheduled to go on vacation Saturday, but talks are expected to continue in his absence.

Lawyers for both sides gathered on Tuesday and Wednesday to put together some of the paperwork that will be needed when a deal on a new collective bargaining agreement is struck.

Players and owners have been holding meetings around the country over the last six weeks, with pressure mounting to break the labor impasse. A major sticking point has been how to divide revenues for a $9 billion business that is easily the most popular professional sports league in America.

Some training camps are set to open in less than three weeks and the first exhibition game, at the Pro Football Hall of Fame in Canton, Ohio, is Aug. 7.

Hall of Fame president Steve Perry has said the plan now is that the game will go on as scheduled.

The Buffalo Bills still appear on track for holding training camp at St. John Fisher College in suburban Rochester. Todd Harrison, a faculty member who works with the Bills in overseeing camp, said school officials, in consultation with the Bills, “continue moving forward” with their plans.

The college issued an email invitation Thursday to training camp staff to attend an annual orientation session on July 18, but Harrison cautioned “not to read too much into that as a signal the Bills are coming.” Harrison said organizers need to be proactive in training staff should a labor agreement be reached next week. The pressure on players and owners to reach a deal has been turned up another notch by the New York attorney general’s office, which has launched an investigation into whether the lockout violates state antitrust laws. The players’ lawsuit, filed in federal court in Minnesota, also is an antitrust case.

New York Assistant Attorney General Richard Schwartz said in a letter to Goodell this week that the lockout will “inflict significant economic injuries statewide.” The New York Jets have canceled their planned training camp in the small upstate city of Cortland, he noted.