Los Angeles:
James Cameron and 20th Century Fox have upped the number of 'Avatar' sequels to the 2009 mega-blockbuster from two to three.
According to a daily, Cameron has selected three sets of screenwriters, including former 'Terminator: The Sarah Connor Chronicles' staff writer and producer Josh Friedman.
'Rise of the Planet of the Apes' writing team of Rick Jaffa and Amanda Silver will work on the second sequel, while 'Armageddon' screenwriter Shane Salerno will focus on the third screenplay.
Production on all three sequels is expected to begin together next year.
It is believed that shooting the three instalments simultaneously could prove to be one of the biggest and most expensive productions in Hollywood history.
