The two companies have been wrangling since last year. In May 2012, Neste Oil Oyj sued Syntroleum for alleged infringement of Neste’s U.S. Patent No. 8,187,344. On January 31, 2013, the United States District Court for the District of Delaware granted Syntroleum’s motion to stay Neste’s lawsuit pending reexamination of the ‘344 patent by the US. Patent & Trademark Office (USPTO).

Previously, the USPTO had granted Syntroleum’s inter partes reexamination request and issued a 14 September 2012 Office Action initially rejecting all claims of the ‘344 patent as obvious in view of the prior art. The ‘344 patent is related to and shares the same inventors as a prior Neste patent (U.S. Patent No. 7,279,018), and both are directed to a fuel composition for diesel engines.

The USPTO’s recent Order is consistent with a prior finding on March 22, 2012 by the USPTO’s Board of Patent Appeals and Interferences affirming the Examiner’s rejection of the ‘018 patent’s claims, the company said. Neste declined to appeal that ruling and on 31 July 2012, the USPTO issued a Reexamination Certificate canceling all claims of the ‘018 patent. The reexamination proceedings involving the ‘344 patent remain pending.

Syntroleum continues to defend a second suit filed by Neste on 20 December 2012 in the District of Delaware alleging patent infringement of U.S. Patent No. 8,212,094. The ‘094 patent covers similar subject matter and shares a common inventor with Neste’s ‘018 and ‘344 patents. Syntroleum denies Neste’s claims and will continue to vigorously defend against the Neste patents.