Kodak has announced its intention to appeal last week's unfavourable International Trade Commission (ITC) ruling in its patent infringement claim against Apple and Research in Motion (RIM).

The ITC concluded that while Apple's iPhone 3G and RIM's BlackBerry devices did infringe Kodak's '218 patent, the patent itself was invalid on "grounds of obviousness based on certain prior art".

Kodak has said it will appeal the decision relating to the invalidy of the patent to the US Court of Appeals for the Federal Circuit.

Kodak's revenue from patent licensing has fallen sharply in the past year and it has been speculated that the ITC ruling could lead to less generous offers in Kodak's patent auction.

The digital manufacturer was given the all-clear to auction a portfolio of 1,100 digital imaging patents by a US bankruptcy judge at the beginning of the month.

Funds raised from the patent auction, which is scheduled to take place on the 8 August, are central to Kodak's plans to successfully emerge from Chapter 11 bankruptcy protection.

So far, more than 20 bidders are reported to have signed non-disclosure agreements with Kodak, with most of the parties expected to reveal their bids shortly before the deadline.

Kodak has said the patents in the portfolio could be worth up to $2.6bn (￡1.7bn); however, patent experts have been less optimistic in their valuations.