In a Wednesday blog post, Richard Waters of the Financial Times suggests that T3 Technologies, a firm that earlier this week filed a complaint with the European Commission accusing IBM of antitrust violations related to its mainframe business, is being backed in its legal fight by Microsoft.

T3 claims that IBM has illegally tied the sale of its operating system to its mainframe hardware in order to shut out competitors. In December 2007, T3 filed an antitrust claim against IBM with the United States District Court for the Southern District of New York.

Waters notes Microsoft in early November invested an undisclosed sum in T3 Technologies that could be the financial fuel for its latest legal salvo.

T3 was an IBM channel partner from 1993 to 2002, during which time the company built a healthy business selling IBM mainframes. But when T3 tried to offer alternative mainframe products to fit their customers' needs, IBM's lawyers swooped in and put a stop to it.

Waters likens T3's situation to that of Platform Technologies, another mainframe solution provider that was sued by IBM in 2006 for patent violations, and, after getting a $37 million cash infusion from Microsoft and other investors, then turned around and filed antitrust suits against IBM in U.S. and European courts. IBM acquired Platform Technologies in July 2008 for an undisclosed sum.

A Microsoft spokesperson contacted by Channelweb.com said Microsoft isn't a party to T3's complaint against IBM, but the company does believe the concerns T3 has raised in both the U.S. and Europe deserve full and fair hearings.

"Like T3, Microsoft believes there needs to be greater openness and choice for customers in the mainframe market. Customers want greater interoperability between the mainframe and other platforms, including systems that run Windows Server," the spokesperson said.

"That's why we continue to invest in companies like T3 Technologies and other startups: to develop new solutions for our mutual customers."