Months after 20th Century Fox CEO Tom Rothman told the media that he hoped Matthew Vaughn would be back for an X-Men: First Class sequel, the deal has apparently been signed between both parties. While talking about Fox's production chief Emma Watts renewing her contract, Deadline confirmed that Vaughn is officially on board a return to the director's chair.
Actor Michael Fassbender (Magneto) has been the most vocal recently with discussions on where he would like to see his character go in a follow-up so it's a given that he's one of those who signed a multi-film deal. Same goes for James McAvoy, the man behind Professor X. Whether the other stars signed multi-film deals for their respective characters, we'll have to wait and find out later down the development road.
At the moment, writer Simon Kinberg (Sherlock Holmes, Jumper) is scripting the sequel out.