A section of the plot is set in the Argentine coastal city of Villa Gesell, but was filmed elsewhere.
"X-Men Origins: Wolverine," starring Hugh Jackman in the title role, opened to $ 85 million in North America. Jackman has a cameo in the new film.
"X-Men: First Class," which reportedly cost about $ 160 million to make before tax credits, is a prequel dealing with the formative years of the future superheroes. Both critics and fans hailed the new direction.
The film is set primarily in 1962 during the Cuban Missile Crisis and focuses on the relationship between Professor X and Magneto and the origin of their groups, the X-Men and the Brotherhood of Mutants.
Even though the North American opening was sharply lower than most of the earlier films in the "X-Men" franchise, it all but guarantees there will be more films revolving around the exploits of a stable of mutant superheroes.
"X-Men: First Class," a relaunch of the Marvel comic book franchise, opened at No 1 across the United States and Canada with $ 56 million -- fulfilling the studio's expectations, even if some analysts were predicting a $ 60 million start.
Other cast members include Kevin Bacon, January Jones, Rose Byrne, Jennifer Lawrence, Zoe Kravitz, Nicholas Hoult and Lucas Till.
Principal photography began on August 31, 2010, in Oxford, England, which included St Aldate's street and some of the University of Oxford's buildings, lasting for two days.
The film has received positive reviews, with the review aggregator website Rotten Tomatoes showing 87 per cent freshness and a rating of 7.4/10 from 169 reviews counted as of June 4, 2011.
The fifth movie in the "X-Men" series took the No 1 spot at the worldwide box office after selling about $ 120 million worth of tickets.
McAvoy and Fassbender play the lead roles originated by Patrick Stewart and Ian McKellen in 2000's "X-Men" and two sequels.
X-Men: First Class is a 2011 American superhero film directed by Matthew Vaughn. Based on the characters appearing in Marvel Comics, it is a prequel to the X-Men film series.
The film stars James McAvoy as Professor X and Michael Fassbender as Magneto.
The film was mostly shot in England and parts of the United States.
The British group Take That provided the film's official song, "Love Love", played during the end credits. It was released May 11, 2011.