Australian open source consultancy Cybersource has said it will file a formal complaint with the country's competition commission against Microsoft for engaging in unfair practices.

Accusing Microsoft of stifling competition in the marketplace, Cybersource will provide the Australian Competition and Consumer Commission (ACCC) with a whitepaper entitled "The cost of software monopoly: how Australian consumers lose", accompanied by a formal complaint. Cybersource claims that Microsoft's practices are costing end users A$200 million (£86.5 million) a year

Cybersource managing director Con Zymaris said users are suffering from a lack of competition in the desktop market and Microsoft is blocking the progress of viable alternatives such as Linux. "In fact, over A$1 billion has been sucked out of Australian customers' pockets just these past five years alone," he said.

The formal complaint requests that an operating system be sold unbundled from hardware and seeks a level playing field for software vendors in the Australian education space.

"Microsoft has a long history of bullying PC vendors who have dared to introduce alternatives to Microsoft on the desktop... we don't know if the PC vendors' hands are tied by invisible shackles orchestrated by Microsoft," Zymaris said.

"However, having the ACCC ensure that the 'no operating system' option is made available is the only way to find out; vendors have always been too scared to act on their own against Microsoft.

"In areas where vendors do not pre-install a Microsoft operating system, for example the server market, Linux has gained around 30 percent of the market and it has led to an increasingly fierce and competitive battle, as should be the case. We want the same battle to occur on the desktop as this can only benefit customers through better products at lower prices."

Zymaris wants education departments across Australia to review their procurement procedures claiming that when they go to tender it is only to select which Microsoft reseller they purchase Microsoft products from instead of seeking out alternatives.

A spokesman for Microsoft was unwilling to comment on the ACCC complaint or respond to the whitepaper.