MasterObjects, a software development company, added Microsoft to the list of companies it is suing for infringing on a patent for technology that displays potential completed search terms as users type into a search bar.
MasterObjects filed similar suits against Amazon and Google in March.
Like those complaints, this one charges Microsoft with infringing on a patent MasterObjects received last year. MasterObjects says that it notified Microsoft in May 2008 of the patent.
Microsoft uses the technology in several products, including Bing, Internet Explorer, Windows Phone and mobile applications that Microsoft offers for iPhone and Android users, MasterObjects alleges.
MasterObjects has been selling products based on the patents since 2004, it said.
The company similarly charged Amazon with infringing the patent in its "search suggestion" feature, which displays a drop-down list of potential search terms as users type into the search bar on Amazon.com. It alleges that Google infringes the patent in Google Instant, Google Suggest and in the search box in Android.
All the cases were filed in the U.S. District Court for the Northern District of California. Other companies, including Yahoo, also use technology for displaying suggested search terms to users.
Microsoft did not immediately reply to a request for comment.