NEW YORK, Dec 18 (Reuters) - Green Plains Inc plans to idle 55 million gallon a year Otter Tail ethanol plant in Fergus Falls, Minnesota, amid weak margins, according to three market sources familiar with the plant's operations.
* Green Plains could idle the plant until spring, given the challenges of restarting the plant in the severe cold temperatures, the source said.
* Green Plains spokesman Jim Stark did not comment on the status of the plant, but said "We have not made any long term decisions on idling plants for an extended period of time."
* Green Plains has idled several plants, sold others, amid a historic downturn in the ethanol market. (Reporting By Jarrett Renshaw and Michael Hirtzer Editing by Chizu Nomiyama)