The European Union’s antitrust authority confirmed yesterday that it is analysing a fresh set of “informal complaints” against Microsoft over its business practices.

These complaints by industry rivals are separate from those that led the European Commission to impose a record fine on Microsoft and order it to unbundle Media Player from Windows and ensure interoperability with its workgroup server software, according to a spokesman.

“The Commission has received a number of informal complaints about Microsoft,” said Jonathan Todd, delivering a prepared statement on behalf of European commissioner for competition Neelie Kroes. The Commission is in the process of analysing the complaints, he continued, and will not take a decision whether to open a new case against the company before this analysis is complete.

The Commission’s statement comes in response to an interview with Kroes in The New York Times, in which the commissioner suggested she would take action against the company over these complaints. “We’re not going to wait and do nothing,” she said in the interview.

The article suggested that the complaints could involve the bundling of products into Microsoft’s Office software suite. But Todd declined to confirm any details of the complaints, commenting only that they were “not new”.

Kroes’ comments about not waiting referred to the 2004 antitrust ruling by the Commission against the company, in which it ordered Microsoft to offer a version of its Windows PC operating system without Media Player and publish its communications protocols for workgroup servers, Todd said.

The Commission insists that the licensing terms for these protocols should include open-source software licences. Microsoft is contesting this, arguing that such licences would violate its intellectual property rights.

Todd said the Commission “is determined to ensure that its decision is fully implemented” by Microsoft.

It has asked Microsoft’s rivals and other industry players for their assessment of whether the company’s offer on licensing terms is reasonable, he added.

“We are still analysing the results of this,” Todd said.

Although the Commission may decide to ask Microsoft to revise its offer, it has already agreed to ask the Court of First Instance, which is hearing the company’s appeal against the ruling, to decide whether the licensing terms should include open-source licences. That appeal is expected to take several years.

Microsoft lodged a second appeal against the Commission in August to ensure that the court addressed the question of licensing terms for interoperability in the workgroup server market.