A U.S. trade body declined to fully reverse a ruling that Apple and Research in Motion Apple did not infringe Kodak's patented technology for digital cameras in cellphones, sending Kodak shares down 17 percent in extended trading.

A U.S. International Trade Commission judge in January had said that Apple and RIM did not infringe Kodak's patented technology because it was invalid.

After reviewing its judge's decision, the commission on Thursday said it was affirming in part, reversing in part, and remanding in part the prior decision.

The ITC set a target date of August 30, 2011, but said the administrative law judge could himself extend the date based on the need for further proceedings.

Kodak filed its ITC complaint against Apple and RIM in January 2010, arguing Apple's iPhone and RIM's camera-enabled Blackberry infringe on a Kodak patent related to a method for previewing images.

It is asking the ITC to bar the importation of Apple and RIM mobile phones and other wireless devices with digital cameras.

Apple has filed a countersuit at the ITC, accusing Kodak of infringing its patented technology. In an initial ruling, Kodak was found not to infringe.

(Reporting by Diane Bartz; Editing by Tim Dobbyn)