By Jan Wolfe

(Reuters) - Alphabet Inc's Google LLC was hit on Monday with a U.S. lawsuit alleging it copied a smaller firm's patented digital advertising technology.

Impact Engine Inc filed the complaint in federal court in San Diego, California, alleging various Google online advertising platforms, including Google Ads and Google AdSense, infringed on six patents.

The allegedly violated patents, granted to San Diego-based Impact Engine between 2011 and 2018, relate to so-called "programmatic creative" technology for rapidly producing and customizing online advertisements.

Google did not immediately comment on the case.

According to the complaint, between 2005 and 2007 Google employees expressed interest in partnering with Impact Engine's co-founders, who disclosed prototypes, documents, and source code.

Impact Engine alleged that, after a series of meetings between the companies, Google copied its intellectual property instead of creating a business partnership.

The lawsuit does not include any claims other than patent infringement.

"We cannot stand by any longer and watch while one of the world’s largest and most valuable companies infringes upon our IP and profits from our hard work and creative inventions," Impact Engine Chief Executive Officer Neil Greer said in a press release.

"We are determined to enforce our intellectual property rights and to protect our innovations, for Impact Engine’s own sake and for the sake of other young companies who might be victimized by behemoths such as Google.”

About 85% of Alphabet’s revenue comes from Google’s ad business, which sells links, banners and commercials across its own websites and apps and those of partners.

(Reporting by Jan Wolfe; Editing by Tom Brown)