The U.S. International Trade Commission ruled on Monday that Kodak did not infringe on Apple's patents, upholding an ITC judge's decision from May.

Apple lodged its complaint with the ITC in April last year as a countersuit to a suit filed by Kodak. The Cupertino, Calif., iPhone maker had alleged that Kodak violated digital imaging software patents with its digital cameras.

In May, a judge for the federal agency sided with Kodak, finding one of Apple's patents invalid and ruling that the struggling photographic company had not infringed on either patent. As reported by Reuters, Monday's decision upholds the ruling, although the companies have ongoing legal disputes in district courts.

"We are pleased that the commission has confirmed the [administrative law judge's] finding that there is no violation by Kodak," said Kodak spokesman David Lanzillo.

After falling 8.03 percent to $2.52 on Monday, shares of Kodak regained some lost ground in after-hours trading. The company's stock has been in free fall, losing more than 50 percent of its value since the beginning of the year.

Investors are likely to more heavily anticipate Kodak's suit against Apple, as the company has said a settlement could bring in as much as $1 billion in royalty revenue.

Kodak first filed its complaint against Apple last January, saying that years of discussions with the company over patent licensing had broken down. BlackBerry maker Research in Motion was also included on the suit.

Earlier this year, Kodak's case against the two companies was found to be invalid by an ITC judge because the patent in question was an "obvious variation of an earlier invention." After reviewing the case, the full commission issued a mixed ruling, upholding some of the judge's decision, while also finding Apple and RIM guilty of infringing on several smaller patents and sending parts of the ruling back to an administrative law judge.

Kodak has previously enforced the patent against Samsung and LG, receiving $950 million in royalties from the two companies. As profits from the camera film market have dried up, the company has resorted to licensing fees from its well-stocked patent portfolio for revenue. According to the report, the company expects to see $250 million to $350 million in licensing revenue each year through 2013.