The first instalment is due out on 14 December and the follow-up on 13 December 2013.
Rumours that a third film was in the works surfaced last week.
They followed Jackson's assertion that he wanted to shoot extra footage, just days after announcing the end of principal photography.
"It is only at the end of a shoot that you finally get the chance to sit down and have a look at the film you have made,"
"Recently I did just this when we watched for the first time an early cut of the first movie - and a large chunk of the second.
"We were really pleased with the way the story was coming together, in particular, the strength of the characters and the cast who have brought them to life.
"All of which gave rise to a simple question: Do we take this chance to tell more of the tale? And the answer from our perspective as the filmmakers, and as fans, was an unreserved 'Yes'."
Jackson said that extending the project to three films
"allows us to tell the full story of the adventures of Bilbo Baggins and the part he played in the sometimes dangerous, but at all times exciting, history of Middle-earth".
"The Hobbit" book is a very small book, (310 pages) guessing the 1st film will be based on it but then then 2nd/3rd will just be added stories. I could be completly wrong though. :thinking about: