There have been widely published reports that the trio will reprise their original trilogy roles for over a year, although there has been no official comment on casting from producers yet.
Fisher - who played Princess Leia – has since been quoted by TV Guide as saying that she will begin shooting director JJ Abrams's new film in March or April.
"I'd like to wear my old [signature Princess Leia] hairstyle again - but with white hair," she quipped. "I think that would be funny."
Michael Fassbender, Michael B Jordan, Saoirse Ronan, Jesse Plemons, Adam Driver and Hugo Weaving have also been rumoured to be in talks for roles in Star Wars Episode 7.
Director Abrams recently confirmed that the script has recently been completed.
Star Wars Episode 7 is scheduled for a December 18, 2015 cinema release.
Photo Gallery: Star Wars saga behind the scenes