* Finland cuts its stake in the operator to 10 pct
* Sale to bolster government finances (Adds background on state ownership, Solidium comment)
HELSINKI, Sept 5 Finland's state investment fund Solidium sold 368 million euros ($485 million) worth of shares in TeliaSonera, cutting its stake in the Nordic telecoms operator to 10.1 percent from 11.7 percent.
The average price of the 68 million shares, which were placed with investors, was 5.41 euros or 47.1 Swedish crowns per share. TeliaSonera shares were down 2.6 percent at 47.23 crowns by 0800 GMT.
"We will use the (TeliaSonera) proceeds mainly to finance our profit distribution to the state," Solidium's managing director Kari Jarvinen said in a statement on Thursday.
A lawmaker told Reuters last month the government would likely trim its stake in TeliaSonera or investment group Sampo , amid efforts to bolster its coffers.
The Finnish coalition government aims to raise half a billion euros a year from share sales to boost revenues and maintain Finland's triple-A rating in the face of falling taxes and rising spending on an ageing population.
Finland is still the second-biggest shareholder in TeliaSonera, a result of a Nordic merger in 2002, after the Swedish state. (Reporting By Jussi Rosendahl; Editing by Erica Billingham)