Two Eastman Kodak directors resigned from the board last week, the struggling photography company said in a filing with regulators on Tuesday.

Both directors - Adam Clammer and Herald Chen - were representatives of private equity firm KKR & Co on Kodak's board. Kodak said Clammer and Chen notified the company of their resignations on December 21.

The two directors joined Kodak's board in 2009, after KKR bought $300 million of Kodak's senior secured notes and warrants to buy 40 million of the company's shares.

No reason given. We thank them for their service, Kodak spokesman Christopher Veronda wrote in a brief emailed statement when asked why Clammer and Chen had resigned. A KKR spokeswoman declined to comment.

Bill Brandt, chief executive of turnaround consultant Development Specialists Inc and chair of the Illinois Finance Authority, said there could be two reasons that board members from the same organization would abruptly resign.

One, they could be about to file bankruptcy. Sometimes if you can see that decision coming, you bail before it happens, and avoid having to be part of a directors and officers liability suit. Or, two, KKR may be trying to increase its stake in Kodak or bid on most of its patents. There would be a conflict of interest if KKR was doing that and its representatives stayed on the board, Brandt said.

Kodak has been struggling to cope with the collapse of its film business due to the dominance of digital photography.

Speculation flared in September that Kodak was on the verge of bankruptcy, after the Rochester, New York-based company hired restructuring experts. Last month, Kodak warned that unless it could raise $500 million in new debt or sell some patents in its portfolio, it might not survive 2012.

Kodak's five-year credit default swaps were quoted at distressed levels earlier this month, reflecting a 92 percent chance of default on its debt in the next five years.

(Reporting By Michael Erman; Additional reporting by Greg Roumeliotis and Nick Brown; Editing by Gary Hill)