Originally scheduled to run through Apr. 5, Conor McPherson's St. Nicholas has extended its Off-Broadway engagement at Primary Stages through Apr. 25.

In this one-person show directed by the author, a lovesick man (a theatre critic!) follows a beautiful actress to London -- and to his own destruction.

According to production spokesperson Karen Greco (of the Tony Origlio press office), St. Nicholas probably won't extend past Apr. 25, since star Brian Cox has film commitments. Scottish actor Cox is a veteran of the National Theatre and RSC in London and a featured actor in such films as The Boxer (as Emily Watson's dad) and Rob Roy. A two time Olivier Award winner, Cox even played Dr. Hannibal Lecter before Anthony Hopkins did (in the film Manhunter).

Other plays by McPherson include The Lime Tree Bower and The Weir. St. Nicholas premiered at London's Bush Theatre.

St. Nicholas, which began previews Mar. 11, features lighting design by Deborah Constantine. For tickets ($30-$35) and information on St. Nicholas at Primary Stages, 354 West 45th St., call (212) 333-4052.

-- By David Lefkowitz and Sean McGrath