By Lesley Savage
Updated June 24, 2009 at 05:19 PM EDT

James Cameron unveiled the first publicly shown clips from his $300 million 3-D sci-fi action-flick, Avatar, during Fox’s presentation at Cinema Expo, according to Hollywood Reporter. When introducing the 24-minute footage, Cameron said much of it came from the first third of the film but that there were also glimpses from unfinished portions of later battle scenes involving warring sides clashing over control of the fantasy world Pandora. Avatar actors Sam Worthington, Sigourney Weaver, Zoe Saldana and Stephen Lang also greeted exhibitors.