A Californian judge has allowed a class action against Microsoft to go to court, to decide charges that the Seattle-based software company used its alleged monopoly to overcharge consumers. The move is a blow for Microsoft because it is the first time such a case has been permitted to go to trial.
There are more than 60 similar suits pending.
Until now, actions in Hawaii, Iowa, Kentucky, Nevada, Oregon, Rhode Island and Texas have all been dismissed. Microsoft shares were the most heavily traded stock by midday yesterday with more than 16.6 million shares changing hands in New York.
The share price was down $1.13 (€1.27) at $69.81 in early trading.
Mr Stuart Pollak, a San Francisco Superior Court Judge, determined that an unspecified number of Californian consumers could be represented in one case to decide whether they had been charged unreasonable prices for Microsoft products.
These include the MS-Dos operating system, Word, the word processing program, and Excel, the spreadsheet.
He argued that consumers would have little incentive to litigate on their own, since the costs would be greater than any sums they might recover.
"This ruling is not unexpected, given California law," said Mr Jim Cullinan at Microsoft. "It is the first step in a long process," he said.
He added that Microsoft was confident that it would be shown that his company's behaviour would be shown to have benefited rather than harmed consumers.
