The upcoming fifth instalment in the "Terminator" series will be called `Genisys`, reveals the franchise's star Arnold Schwarzenegger.

Schwarzenegger is due to reprise his role in the new film, which is expected to come out in 2015.

He spilt the name of the new film via his Instagram page as he thanked the cast and crew after production of the reboot had finished earlier this week, reports contactmusic.com.

"Hasta la vista, baby. I want to thank the cast and crew of @TerminatorGenisys for a fantastic shoot," he posted.

He also mooted a release date of July 1 next year for the new movie.

The former Governor of California has not appeared in franchise since `Terminator 3: Rise of the Machines` back in 2003.

The unusual title could well be a reference to a new high-tech manufacturing corporation or some kind of apocalyptic event, being a portmanteau of the words 'genesis' and 'system', like Cyberdyne and Skynet in previous instalments. It would certainly fit well with the existing mythology of the series.