UPDATE 1-Nuclear energy boosts Fortum power unit in Q4

* Q4 Power unit comparable op. profit 351 mln euros

* Shares up 5 pct

* Hedged 65 pct of 2012 volumes at 48 euros/MWh (Releads, adds share reaction, analyst quotes)

HELSINKI, Feb 1 (Reuters) - The restoration of some nuclear plants helped Finnish utility Fortum's power generation business turn more profitable in the fourth-quarter, the company said on Wednesday.

The power generation unit's comparable operating profit, which excludes hedging, rose 4.5 percent from a year earlier to 351 million euros ($459 million), beating forecasts.

Fortum's shares rose 5.1 percent to 17.65 euros by 1205 GMT as investors cheered improved efficiency at the plants, including those in Sweden that had been hit by disruptions such as fires and prolonged maintenance in the past few years.

"Utilisation rate at Fortum's nuclear power plants in Sweden was good," said Nordea analyst Pasi Vaisanen.

The company also increased hedging for this year, a strategy analysts said could work in its favour because prices were trending down.

Fortum said it had hedged 65 percent of Nordic electricity volumes at 48 euros per megawatt hour for 2012 and 40 percent at 46 euros per megawatt hour for 2013.

Analysts said the hedging and strength in the power generation business helped investors disregard a fall in quarterly operating profit.

The group's operating profit was 508 million euros, down from 541 million euros a year ago, and missing an average market estimate of 515 million euros in a Reuters poll.

Fortum blamed that on a year-end storm which cut off electricity connection to thousands of customers. Fortum estimated the storm would cost it 57 million euros.

The company proposed a dividend of 1.00 euro per share, in line with market expectation.

($1 = 0.7639 euros) (Reporting by Terhi Kinnunen, Editing by Mark Potter)