EXCLUSIVE

Lindsay Lohan will not face charges for her arrest in that New York City nightclub brawl with another woman ... TMZ has learned.

Law enforcement sources tell us the Manhattan D.A.'s Office will not prosecute Lohan -- and we're told the main reason is ... witnesses failed to cooperate.

TMZ broke the story ... Lindsay was busted back in November for allegedly punching the woman inside Club Avenue.

We're told witnesses to the incident, including those connected with the alleged victim, refused to speak to investigators.

Another problem with the case ... according to our sources on the night of the fight ... the woman was being escorted out of the club by police, and tripped and fell ... so it was unclear what really caused her injuries.

The Manhattan D.A. would not comment.

LiLo skates again.