(Reuters) - A small group of National Hockey League (NHL) owners and players appeared to be making some progress on Wednesday toward ending a costly lockout that threatens to wipe out a full season of play for the second time in seven years.

Pittsburgh Penguins captain Sidney Crosby was among 18 players who met with six NHL owners at a Manhattan hotel for a second consecutive day of marathon negotiations that continued for almost nine hours before ending well past midnight.

Further talks are planned for Thursday as the two sides attempt to find a common ground in pursuit of a new collective bargaining agreement.

"We obviously had a number of meetings today over many hours," NHL Deputy Commissioner Bill Daly told reporters. "Had good, candid dialogue on a lot of issues.

"There continue to be some critical open issues between the two parties and we understand the (players') union should be getting back to us (Thursday) on some of those issues."

The two sides met for eight hours on Tuesday and briefly on Wednesday morning before a short break to accommodate a previously-scheduled NHL Board of Governors meeting.

"We are pleased with the process that is ongoing and out of respect for that process I don't have anything else to say and I'm not going to take any questions," NHL Commissioner Gary Bettman told reporters before talks reconvened in the afternoon.

Neither Bettman nor NHL Players' Association Executive Director Donald Fehr were involved in the owners-players meetings.

FAILED MEDIATION TALKS

This week's discussions, aimed at ending a lockout that has already canceled about one-third of the 2012-13 NHL season, were the first between the two sides since U.S. federal mediators failed to kickstart talks last week.

The NHL and the union representing its players have been without a collective bargaining agreement since mid-September, resulting in the scrubbing of 422 regular season games and the All-Star Weekend in Columbus that was scheduled for January.

The lockout, which the NHL has said is costing it about $18-$20 million per day, is centered around a dispute over how to split the league's $3.3 billion revenue. It is the fourth work stoppage in 20 years for the NHL and the first since a lockout led to the cancellation of the 2004-05 season.

While both sides have agreed in principle to a 50-50 split of hockey related revenue, they remain at odds over how to reach the target.

Owners are demanding an immediate reduction from the 57 percent players received under the previous agreement, while the union would like to see the cuts brought in gradually.

The players and owners also have deep differences on several other key points, including contract restraints and free agency.

(Reporting by Frank Pingue in Toronto and Mark Lamport-Stokes in Los Angeles; Editing by Larry Fine and Amlan Chakraborty)