Zak Penn has been hired to work on a script for the follow-up to the 2010 remake, reports Variety.
The sequel was first announced in 2010, with the writers of Kung Fu Panda rumoured to be working on the script.
No actors have been cast in the movie at present, but Jackie Chan and Jaden Smith are both being sought to reprise their roles.
Penn's last feature was 2008's The Incredible Hulk. He has since been writing and producing the television show Alphas.
The original 1980s Karate Kid trilogy starred Ralph Macchio and Pat Morita.
Macchio has said that he has no interest in appearing in another Karate Kid movie.
Watch the trailer for 2010's The Karate Kid below: