Some 1,000 white-collar paper workers held a two-week strike at UPM mills across Finland that started on 6 April and ended at 6am today (20 April), following a breakdown in the latest round of wage negotiations.

Jyrki Ovaska, president of UPM's Paper Business Group, said in a statement that the cost impact was "smaller than anticipated".

"Thanks to large special arrangements and the flexibility of other employees we managed to secure our customer deliveries and keep production lines running except one paper machine at our Tervasaari mill," said Ovaska.

"Unfortunately, resulting from the strike, delays in UPM's payment traffic will continue for weeks."

The Finnish Forest Industries Federation and the trade union Pro will continue their negotiations without a resolution.

Negotiations will recommence on 26 April, and Pro has announced it is expanding the salaried paper industry employees' strike to Stora Enso, Metsäliitto and Myllykoski Paper for a two-week period starting on Wednesday 27 April. The planned strike does not include UPM.

UPM was unavailable for further comment at this time.