HarperCollins said yesterday it will shutter its controversial Regan Books unit, closing the Los Angeles office on March 1 and scrapping a controversial novel about Mickey Mantle.

Judith Regan, the former head who had pushed the O.J. Simpson confessional novel “If I Did It,” was fired in December for allegedly making anti-Semitic remarks. Regan’s lawyer, Bert Fields, denied his client made such remarks.

The firm is owned by News Corp., which also owns The Post.