The European Commission is investigating whether Microsoft .Net Passport breaches European privacy laws, a spokesman confirmed Monday.

The Commission, the executive body of the European Union (EU), launched its probe in response to a complaint against .Net Passport by Erik Meijer, a Dutch member of the European Parliament, EU spokesman Jonathan Todd said.

Meijer said that by failing to register with .Net, passport users are being excluded from many Web services. He is also unhappy that unsubscribing from .Net Passport is impossible.

The European commissioner for the internal market, Frits Bolkestein, wrote in a letter to Meijer, dated May 7: “The Commission is looking into this as a matter of priority, in concert with national data-protection agencies, as regards the system’s compatibility with EU data-protection law.”

Immunity Microsoft signed up to the EU/US safe harbour agreement in 2000. The agreement allows signatory companies from the US immunity from some of the tougher privacy laws to be found in Europe. However, in return, the companies agree to abide by EU laws.

The probe into .Net Passport is unconnected to the ongoing antitrust investigation being conducted by the European Commission. The European regulator believes that the software giant has been abusing its dominance of PC operating systems to squeeze out rivals in the market for server software. It also believes that, by bundling Media Player into Windows, Microsoft is putting competitors at an unfair disadvantage.

The antitrust case continues. All information from Microsoft and from third parties complaining about the company was gathered last month.