Lucas sold Lucasfilm to The Walt Disney Co. this week for $4.05 billion and announced three more "Star Wars" sagas are in development.
Hamill told EW.com Lucas confided in him and his "Star Wars" trilogy co-star Carrie Fisher in August that there would be three "Star Wars" sequels.
Asked how he reacted to the news of the sale of Lucasfilm to Disney, the actor told EW.com: "Oh my gosh, what a shock that was! I had no idea that George was going to sell to Disney until I read it online like everybody else. He did tell us last summer about wanting to go on and do [Episodes] VII, VIII, and IX, and that [newly appointed Lucasfilm president] Kathleen Kennedy would be doing them."
So, did Lucas divulge any details about where the story would go in the next three films and whether Hamill's Luke Skywalker character would appear in them?
"Well, no, he was just talking about writers and the fact that he wouldn't be directing," Hamill told EW.com. "I guess he wanted us to know before everybody else knew. He said, 'Now you can't tell anybody!' Even now, I'm nervous about saying anything. I just don't know."