The actor told Empire that he was forced to reject the role "with a heavy heart" because of a potential clash with filming on BBC's Sherlock, in which he stars as Doctor Watson.
Freeman said: "I did have to say no to it for the second series of Sherlock, but if something could be worked out, that would be great."
Asked if the changing production date of the Lord Of The Rings prequel could make him available for the role, Freeman said: "I'd like to think so. If there is any outside possibility, then that would be great. But I've learned not to think too much or hope too much about stuff. It will happen if it happens."
Freeman said of the original JRR Tolkien series: "I wasn't a fan of it as a kid but I did like the films. I think Ian [McKellen] is very good, and [director Peter] Jackson's a clever man. I thought what he did with them was interesting and entertaining."