Microsoft Corp. has two years in which to convince Amsterdam city authorities that it can offer better value for money on the desktop than open source alternatives.

The city will conduct tests of open source software on desktops in two departments in the first half of 2007, it said Friday.

It doesn't intend to phase out the use of proprietary software completely, but expects the tests to lead to a reduction in the scope of its contract with Microsoft, its current desktop software supplier, the city said. That contract expires at the end of 2008, according to a statement from the city.

Two departments, the city's housing service, and the local authority for the borough of Zeeburg, will test the Linux operating system on desktop PCs, city authority spokeswoman Marjolijn van Goethem said Thursday.

A study conducted for the city council earlier this year showed that the use of open software ensures better exchange and storage of digital information, the city's statement said.

Amsterdam is not alone in considering the switch from proprietary to open source desktops: The German city of Munich is in the process of migrating desktop PCs to the Linux operating system.

Other local and national administrations around Europe have cited safeguarding access to their own data as a reason for preferring software based on open source and open standards over proprietary applications. The Belgian government voted earlier this year to adopt the Open Document Format (ODF) popularized by the open-source desktop productivity suite OpenOffice.org for document storage and exchange, while authorities in France and Denmark are also evaluating the benefits of ODF.