Nord Stream plan wins final Finnish approval: source

HELSINKI (Reuters) - Finnish environmental authorities have approved construction of the Nord Stream gas pipeline through Finland's waters, clearing the way for Russia to start its biggest post-Soviet gas pipeline, a source said.

The source, who has knowledge of the decision, spoke on condition of anonymity. A decision from authorities is due on Friday at 0600 GMT.

The approval marks a major step forward for Russia's plans to diversify its energy export routes to Europe, but some analysts say the pipeline is too expensive and could face delays due to the economic downturn and lower demand for the fuel.

Nord Stream, a project involving Gazprom, Germany's BASF and E.ON as well as Dutch Gasunie, plans to transport 55 billion cubic metres of gas per year from Russia to Germany when completed in 2012.

Nord Stream will connect to the European energy grid in Germany.

(Reporting by Brett Young and Terhi Kinnunen)