NFL owners and players' association leaders met for more than 12 hours Thursday at New York, failing to reach a deal to end the league's months-long lockout but are returning to try again today.

"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 today.

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.

Mackey dies: John Mackey, the rugged Hall of Fame tight end and union president who later fought for stronger health benefits of retired players and struggled with dementia, died. He was 69.

Mackey's wife notified the team about her husband's death, Baltimore Ravens spokesman Chad Steele said Thursday. No official cause was given.

Mackey played for the Baltimore Colts from 1963-71, and helped the team beat the Dallas Cowboys in the 1971 Super Bowl by catching a pass from Johnny Unitas after it deflected off two other players for a 75-yard touchdown.

He also played for the San Diego Chargers in 1972, and finished his 10-year career with 331 catches for 5,236 yards and 38 touchdowns.

Mackey's efforts after his playing days were just as important as his performance on the field. An NFL labor agreement ratified in 2006 includes the "88 Plan," named for Mackey's number, 88.