GANTZ:O will arrive in Japanese theaters on October 14th, and is an adaptation of the Osaka arc. The production team includes Keiichi Satou(Tiger & Bunny) as executive director, screenplay by Tsutomu Kuroiwa (One Piece Film Gold), general direction by Yasushi Kawamura (CGI director for Appleseed: Ex Machina), and production by Digital Frontier.
Check out the first teaser: