Natalie Portman pulls out of Thor films

Chris Hemsworth as Thor and Natalie Portman Jane Foster in the Marvel movie Thor.

Natalie Portman will not be reprising her character in the upcoming superhero sequel, Thor: Ragnarok.

The Oscar-winning actress played Jane Foster, love interest of Chris Hemsworth's Asgardian god, in the previous two movies - 2011's Thor, and 2013's Thor 2: The Dark World.

But Marvel Studios boss Kevin Feige revealed on Friday that Natalie would not appear in the next movie Thor: Ragnarok, which is due to be released in 2017.

Natalie Portman as Jane Foster in a scene from Marvel's Thor: The Dark World.

"(There are) many reasons (she won't appear), many of which are in the film, so you will see that," Kevin told the Empire Film Podcast. "There are only a couple scenes on Earth in this movie. The majority, 95 per cent of the movie, takes place in the cosmos."

He also stressed that a third movie in a film series provides "the opportunity and the time to really change things up".

Jane Foster was mentioned in last year's Avengers: Age of Ultron movie, during a conversation between Robert Downey Jr.'s Tony Stark and Thor, but was not actually seen.

Her last appearance in the Marvel universe was in Thor: The Dark World, which featured her character being poisoned by a powerful entity known as the Aether, bringing about a near-apocalypse.

A scene from Marvel's Thor: The Dark World.

While Natalie is not yet returning to the superhero franchise, Chris will reprise his hammer-wielding role for the third Thor instalment, while Mark Ruffalo will be returning as Bruce Banner / Hulk. Tom Hiddleston, Cate Blanchett and Jaimie Alexander are also confirmed to be starring in the superhero movie.

- WENN