Firefox developer Mozilla has been granted permission by the European Commission to join its antitrust case against Microsoft. Mozilla now has "interested third party" status, which allows the company to submit arguments to the European Commission, according to PC World.

Microsoft has been accused by the European Commission of unfairly trying to control the Web browser market by bundling Internet Explorer with its Windows operating system.

Mozilla chairperson Mitchell Baker commented that there isn't an "iota of doubt" that bundling Internet Explorer with Windows "harms competition between web browsers, undermines product innovation and ultimately reduces consumer choice."

Despite Mozilla's strong stance against bundling Internet Explorer with Windows, the company isn't a complainant in the case like rival Web browser developer Opera. Instead, Mozilla will be offering guidance on how the European Commission should proceed with its case. The company will also have access to the confidential statement of objections the commission sent Microsoft, and can participate in an in-person hearing if requested by Microsoft.

Microsoft's Internet Explorer is the market-dominant Web browser, with Firefox coming in at a distant second, and Apple's Safari in third place. Internet Explorer's market share has, however, been on a steady decline for about a year while Firefox and Safari have been gaining new users.

There is no word yet on what penalties or requirements the European Commission might impose on Microsoft.