The union that represents ranking officers of the New York Fire Department is requesting a new investigation into a fire near ground zero that killed two firefighters.

The request by the Uniformed Fire Officers Association comes after a contractor was acquitted Wednesday of manslaughter and other charges in the 2007 fire at the former Deutsche (DOY'-chuh) Bank building.

The company he worked for was found guilty of a misdemeanor.

The union is asking Manhattan District Attorney Cyrus Vance Jr. to examine the role of the Lower Manhattan Development Corp., the city-state agency that owned the building.

Union head Alexander Hagan accused the LMDC of negligence in a letter to Vance on Thursday.

The district attorney's office had no comment. A spokesman for the LMDC did not immediately return a call seeking comment.