Newspotted

By Essi Lehto

• Construction of Finland's OL3 reactor began in 2005

• Work was originally schedule for completion in 2009

• Completion boosts Finland's energy security

• Reactor is expected to produce for 60 years or more

HELSINKI, April 15 (Reuters) - Finland's much-delayed Olkiluoto 3 (OL3) nuclear reactor, Europe's largest, began regular output early on Sunday, its operator said, boosting energy security in a region to which Russia has cut gas and power supplies.

Nuclear power remains controversial in Europe, primarily due to safety concerns, and news of OL3's start-up comes as Germany on Saturday switches off its last three remaining reactors, while Sweden, France, Britain and others plan new developments.

OL3's operator Teollisuuden Voima (TVO), which is owned by Finnish utility Fortum (FORTUM.HE) and a consortium of energy and industrial companies, has said the unit is expected to meet around 14% of Finland's electricity demand, reducing the need for imports from Sweden and Norway.