IBM's decades-long dominance in the mainframe market is under fire, with news that a new anti-trust case, citing abuse of its monopoly position, could be initiated against the computer giant.

The New York Times reports that the US Justice Department has begun a preliminary probe, with anti-trust regulators asking for competitors to tender information about IBM's business practices.
Earlier, a complaint was laid by the Computer & Communications Industry Association, which includes IBM competitors, saying that IBM blocks efforts for other companies to licence IBM's mainframe software and stifles competition in the large hardware and software environment.
Just last weel, a US court rejected a civil suit brought against IBM by T3 Technologies, which resells mainframes. T3, however, plans to appeal the decision.
The last time IBM was embroiled in an anti-trust suit regarding its mainframe business, it dragged on for 13 years before being dropped in 1982.
The new probe is still in its early stages and may not result in an anti-trust case.
About 25% of IBM's revenue comes from mainframes and associated hardware, software and services.