Patent reform was supposed to make patent litigation less common and less costly. But it could wind up costing Versata Software Inc. a whopping $391 million, if SAP America Inc. and its lawyers at Finnegan, Henderson, Farabow, Garrett & Dunner get their way.

On Sept. 16, SAP petitioned the U.S. Patent and Trademark Office to review a Versata patent that SAP was found to have infringed by a jury last year, in one of the biggest patent showdowns of 2011. The filing makes SAP among the first to take advantage of new post-grant review provisions of the America Invents Act that took effect the same day — exactly one year after President Barack Obama signed the AIA into law. The new rules allow anyone charged with infringement of a business method patent to request that the USPTO cancel one or more of the patent’s claims. Other types of patents will be eligible for post-grant review after the final phase of the AIA is implemented next March.