US pressure group Citizens Against Government Waste (CAGW) has expressed "outrage over the draconian punishment" handed down by the European Commission to Microsoft for violating European antitrust laws.

The Commission has ordered Microsoft to unbundle its software and pay a record €497m (£331m) fine.

"The decision by the EC will have a global impact of negative consequence," said Tom Schatz, president of CAGW, in a statement.

"In most international antitrust cases, courts will rely on precedent if a decision has been made in another jurisdiction.

"This is to ensure stability in the global marketplace. Microsoft had already reached a fair agreement in US courts that the EC should have followed.

"The EC should not be making decisions that are best left to the marketplace. Attempting to restrict the future design of software is unprecedented and has been rejected by the US courts."

Schatz also warned that forcing Microsoft to give up many of its intellectual property rights would be a dangerous setback to innovation, as sharing information with competitors would reduce companies' motivation for designing new products.

CAGW added that, with 95 per cent of the world's computers using Windows operating systems, the antitrust decision would not affect only Europe.

"As the rest of the world continues to grow technologically, Europe will lag behind if it does not change its mindset," said Schatz.

"The EC should not have issued a decision that defies precedent and will have such a negative impact on the global economy."

CAGW is non-profit organisation with one million members and supporters across the US. It states its aims as eliminating waste, mismanagement and inefficiency in the federal government.