Warner Brothers said it was "deeply saddened" by Friday's massacre at a Colorado screening of its latest Batman movie, as it cancelled a red carpet premiere in Paris.
British actor Gary Oldman, a co-star of "The Dark Knight Rises," meanwhile expressed shock at the "horrific" shooting, which left at least 12 people dead and nearly 60 injured.
"Warner Brothers is deeply saddened to learn about this shocking incident," the studio said in a statement. "We extend our sincere sympathies to the families and loved ones of the victims at this tragic time."
In France, a scheduled gala premiere of "The Dark Knight Rises" in Paris was cancelled, along with media events with director Christopher Nolan and cast members, cinema management said.
Stars including Christian Bale, Anne Hathaway, Marion Cotillard and Morgan Freeman had been due to attend the premiere on the Champs-Elysees in Paris ahead of the film's general opening in France on Wednesday.
But management at the Gaumont Champs-Elysees cinema, speaking on condition of anonymity, said the premiere had been scrapped.
Oldman, who plays Gotham City police commissioner James Gordon, meanwhile issued a statement saying: "My prayers and deepest sympathies are with the victims and their families of this horrific act."
Police in Aurora, Colorado named the suspected gunman as James Holmes, saying he surrendered without incident after the massacre, during which he was dressed in full black body armor.
He also wore a gas mask, presumably to protect himself from the effect of two tear gas-type devices that he detonated in the theater shortly before opening fire.