One of the highest-profile solidarity strikes forced Finland's national airline Finnair to cancel around 300 flights between Sunday and Tuesday.

But chief labour conciliator Vuokko Piekkala - whose position is nominated by the government every four years to solve disputes - said a resolution was found on Wednesday to settle the wage dispute at Posti.

"Both parties have accepted my proposal for a settlement," she said, referring to employee and employer representatives, who accepted, among other conditions, that pay rises will not exceed a level to be defined at later negotiations.

Posti, where 10,000 of its 15,600 employees had gone on strike halting all paper mail, confirmed its operations would return to normal as soon as possible.

"We are ready for both the Black Friday and Christman season online shopping," Posti's head of emergencies Jarmo Ainasoja said in a statement.

The mail service has been struggling to cope with falling volume and profitability.

Other disputes, however, are far from over in the Nordic eurozone member where wages and working conditions are mostly bargained collectively between employee and employer unions at national level and validated for several years.

The Finnish Forest Industries Federation said on Wednesday it would hold a six-day lockout from Dec. 12, closing half of the country's sawmills and plywood factories, aiming to put pressure on unions in halted pay negotiations.

The employer federation's announcement came after industrial workers and two other unions called a three-day strike for Dec. 9-11 which would involve some 100,000 workers and largely stall production at companies such as oil refiner Neste, Nokian Tyres and Outokumpu.

That action is about wages and working hours.

With many key industry contracts expiring soon, more strike announcements could follow suit in the coming months in Finland.

Finland's labour unions have traditionally been strong and in recent years they have been angered by a so-called "competitivity pact", which increased working hours by three days a year without a pay rise between 2016 and 2019.

The deal was negotiated in 2015 under the previous centre-right government to help Finland's economy recover from recession, but the new centre-left government in office since June has proven more favourable to employee concerns.

"It is important for the state as an owner that employees' working conditions are not being trampled upon (at Posti)," said Finland's Prime Minister Antti Rinne of the Social Democratic Party after Wednesday's agreement was announced.

By Anne Kauranen