We previously reported that the Cannes Film Festival, where X-Men: The Last Stand is screening out of competition, had listed a running time of 1 hour and 43 minutes for the third film.
As we expected, this was simply a guess by the festival because 20th Century Fox couldn’t confirm the true length of the film in time for their schedule to be published. As of today, no running time has been locked in yet, so stay tuned.
X-Men was 104 minutes and X2: X-Men United ran 133 minutes.
Source: 20th Century Fox