Microsoft has, so far, failed to offer the European Commission grounds for a settlement in the long-running antitrust lawsuit against the company, according to a senior antitrust official.
"We still have outstanding concerns," said Philip Lowe, the most senior civil servant in the commission’s competition division.
The commission is understood to be nearing the end of its five-year-long investigation into Microsoft’s business practices.
Officials handling the antitrust case are still in contact with Microsoft's lawyers, Lowe said. "If there was no dialogue [with Microsoft] then we would take a negative decision."
The commission is investigating whether Microsoft is extending its monopoly in the market for operating systems software into the market for low-end computer server software. The case concerns Windows 2000 and all previous versions going back to Windows 95.
The commission has also accused Microsoft of stifling competition in the market for video and audio playing software by bundling its Media Player software into those versions of Windows.
Unless Microsoft comes up with a satisfactory solution that would ensure fair competition in these markets, the commission will impose remedies on the company. It could impose a fine on Microsoft of up to about $3bn (£1.88bn) or 10% of the company's global annual sales.
Late last year commission officials said the case was likely to conclude before August but no date had been set for a ruling. "As long as we have outstanding concerns we will continue pursuing the case," Lowe said.
Microsoft officials were unavailable for comment.
Earlier this year, some of Microsoft’s fiercest rivals submitted a fresh complaint to the European Commission, accusing the software maker of continuing its monopolistic behaviour with its Windows XP product.
Innovation and competition in the development of software for machines from PCs to mobile phones are under threat from the dominance of the latest Windows version, claimed the Computer and Communications Industry Association (CCIA), a trade body representing companies, including Sun Microsystems and Oracle.