THR – Chris Pine and Chris Hemsworth are no longer boldly going where no person has gone before.

The two actors were in negotiations to star in Star Trek 4, but sources say that talks between the two actors and the companies making the new installment, Paramount Pictures and Skydance Media, have fallen apart, with both sides walking away from the table.

Dealmaking with other returning castmembers — including Zoe Saldana, Zachary Quinto, Karl Urban, Simon Pegg and John Cho — was expected to follow.

Pine was due to reprise his role as iconic sci-fi hero Captain Kirk, which he has inhabited for three movies, while Hemsworth was to have played his father in a time-traveling adventure. (Hemsworth played the role in the prologue of the 2009 film that rebooted the franchise.)

At the Paramount Pictures CinemaCon presentation this afternoon in Las Vegas, CEO Jim Gianopulos discussed upcoming films for the studio, including Star Trek. According to The Hollywood Reporter’s account of the event “Gianopulos also teased the studio was developing more in the Star Trek universe with studio partner Skydance. He provided no new details, though Quentin Tarantino is known to be developing a Trek film with J.J. Abrams.”

Gianopolus’s mention of two Star Trek films in development was also reported by multiple members of the entertainment press on hand at the annual event. According Fandango’s Erik Davis, Gianopulos “first he said ‘several new Star Trek movies’ and then clarified that it was two right now in the works.”

Earlier this month it was reported Paramount had plans for at least one more Trek movie, as quoted by Zachary Quinto himself:

“Which ones are going to happen, which ones might happen first? I can’t really say, I don’t know honestly. I know there are lots of conversations being had about it. I know there are plans afoot to do at least one if not more movies.”