Fourteen Hours (1951)
The Italian poster of this movie can be seen.
Donald mentions the movie by name.
Reference to Grace Kelly's only previous film appearance
While Man on a Ledge is not a straight-up remake of the 1951 film Fourteen Hours, is has the similar jumper theme. One noted connection is that the primary action takes place at the same hotel, The Roosevelt, but on different floors.
In a review of Man on a Ledge, David Stratton says that he thought the main character was going to be on the ledge for the entire movie like Richard Baseheart in Fourteen Hours