He is famed as the God of Thunder, but Thor is to change sex, launching an "all-new era" for the comic book icon, its publishers said Tuesday.

Marvel Comics will introduce the female Thor in its latest comic series in October, it announced, stressing that the new Thor is not "She-Thor" or "Thorita."

It was not immediately clear if the sex change will be taken over in the movie version of "Thor," a huge box office hit in recent years.

"The inscription on Thor's hammer reads 'Whosoever holds this hammer, if HE be worthy, shall possess the power of Thor'," said Marvel editor Wil Moss.

"Well it's time to update that inscription."

He added: "The new Thor continues Marvel's proud tradition of strong female characters like Captain Marvel, Storm, Black Widow and more. And this new Thor isn't a temporary female substitute -- she's now the one and only Thor, and she is worthy!"

"This is not She-Thor. This is not Lady Thor. This is not Thorita. This is THOR. This is the THOR of the Marvel Universe. But it's unlike any Thor we've ever seen before," added series writer Jason Aaron.

The change of gender is not unprecedented for Marvel, which was bought by entertainment giant The Walt Disney Company in 2009. Captain Marvel used to be male, but is now female, a spokesman said.

On the big screen Thor has been portrayed by Australian actor Chris Hemsworth in two "Thor" films as well as 2012's record-breaking "The Avengers." He will reprise the role in "Avengers: Age of Ultron," due out next year.

It is unclear whether the hunk actor will have to hang up his hammer, to be replaced by a female version.

"This is a publishing-only initiative," Marvel Entertainment spokesman Joe Taraborrelli told AFP.

A Disney spokeswoman, Megan Wasserman, added: "The announcement... was about the comics, and as normal Marvel policy we cannot (comment) on film activities, rumors or related speculation."