Sigourney Weaver is to feature in a new sci-fi movie being shot in 3D.

Avatar is being made by Titanic director James Cameron, who previously worked with Weaver on Aliens.

Shooting begins in April and the movie is expected to be released in the summer of 2009, according to the Hollywood Reporter.

Avatar will be one of the first mainstream films to be made in 3D only.

Cameron said: "Sigourney and I have always looked back fondly on our collaboration in Aliens, and we're excited at the prospect of working together again.

"She has a unique blend of strength, sensitivity and intelligence needed to play the character of Grace, and she has a special significance for fans of science fiction.

"So in addition to being perfect in all ways for the part, there is something special about her returning to the genre in our film. I was thrilled when she responded so strongly to the script, and I can't wait to see what she creates."

Source: Press Release