Software maker needs to demonstrate that Windows-Explorer tie doesn't harm competition.
The European Union's competition watchdog is insisting that Microsoft respond by June to charges that bundling the Internet Explorer Web browser with Windows is an "abuse" of its dominant position in the computer market.
The company is slated to respond to the allegations orally in closed-door meetings to be held June 3 to June 5 in Brussels, Belgium. In January, the EU's European Commission charged Microsoft with using monopolistic practices to crush competition in the software industry.
"Microsoft's tying of Internet Explorer to the Windows operating system harms competition between Web browsers, undermines product innovation, and ultimately reduces consumer choice," the European Commission charged at the time.
Perhaps in response, Microsoft has disclosed that the forthcoming Windows 7 operating system contains a switch that allows consumers to easily deactivate Explorer in favor of an alternate browser.
The EC claims that Explorer controls the lion's share of the Web browser market and that its built-in presence on Windows "distorts competition on the merits between competing Web browsers insofar as it provides Internet Explorer with an artificial distribution advantage which other Web browsers are unable to match."
The commission said it could impose fines on Microsoft or force the company to ship versions of Windows in Europe that do not include Explorer.
Microsoft has said it would study the EC's objections. It may already have a convincing defense. Explorer's share of the browser market has eroded significantly over the past year, falling from more than 73% in June of 2008 to about 66% in April, according to market watcher Net Applications.
Rival offerings from Apple, Google, and Mozilla have gained share during the same period.
Microsoft and European trustbusters have butted heads numerous times. Last year, the EC hit the company with a record $1.35 billion antitrust fine, claiming that Microsoft failed to make available to rivals documentation needed to create products that are interoperable with Windows.
The EC ordered Microsoft to make the documentation available under "reasonable terms." Previously, the EC had ordered Microsoft to ship a version of Windows Vista that did not include Windows Media Player.