ENGLEWOOD, Colo., Aug. 14, 2012 /PRNewswire/ -- Gevo, Inc. (NASDAQ: GEVO) filed a lawsuit for declaratory judgment against Butamax™ Advanced Biofuels, LLC (Butamax), E.I. DuPont de Nemours and Co. (NYSE: DD), BP p.l.c. (NYSE: BP), BP Corporation North America Inc. and BP Biofuels North America LLC, seeking a judicial determination that a recently issued Butamax U.S. Patent No. 8,241,878 ('878 Patent) is invalid and that Gevo does not infringe on it. "We believe Butamax's patent is invalid and will be filing a Request for Reexamination with the U.S. Patent and Trademark Office," said Brett Lund, Executive Vice President and General Counsel of Gevo. "We can make this claim for many reasons, including the fact that we already have an issued patent covering this technology and we invented it before Butamax filed its patent application. Butamax's '878 Patent covers only two Dihydroxy-Acid Dehydratase (DHAD) enzymes, unlike Gevo's patented technology in U.S Patent No. 8,232,089 ('089 Patent) that covers dozens of DHADs, including the two DHADs claimed in Butamax's '878 Patent." On July 31, Gevo filed a lawsuit in the U.S. District Court of Eastern District Texas charging infringement of Gevo's DHAD technology in its '089 Patent by DuPont, BP, and Butamax. In a lawsuit filed today, Butamax alleged that Gevo infringes its '878 Patent. In Gevo's opinion, Butamax's lawsuit appears retaliatory as Gevo has already sued Butamax and its parent companies for infringing Gevo's DHAD technology in July and today Gevo sued them again for a declaratory judgment. "Gevo has advanced well beyond the R&D stage. We are now operating commercially," Lund said. "We believe this action is an attempt by Butamax and its corporate parents to impede our progress. They are trying to use the courts to compensate for their lack of progress."