Stora Enso is the latest producer to be hit by a two-day wildcat strike. It started on 8 May and affected all of its mills in Finland.

Around 8,000 members of the Finnish Paper Workers Union walked out, shutting down all of the firm's 15 Finnish mills.

Stora Enso's senior vice president for investor relations Keith Russell said although talks were continuing between employers and the unions, both sides seemed more determined than ever.

About 30% of Stora Enso's total production is in Finland, and Russell warned that if hit by strike action, all stockists of grades from the country could be hit quickly by supply shortages.

Some of the main products are coated woodfree and coated mechanical grades, mainly used for magazine paper production.

If talks between employers representatives the Finnish Forest Industries Federation (FFIF) and the Paper Workers Union fail, the FFIF has threatened workers with a two-week lockout from 18 May.

This could lead to production losses of 840,000 tonnes, equivalent to around 381m (E560m) for Finnish manufacturers.

Stora Enso estimated that any nationwide stoppage in Finland could cost it up to 2m per day.

The main sticking points in talks between the mills and the unions are the Christmas and mid-summer shutdowns and the outsourcing of non-core duties.

The aim, Russell said, was to ensure that Finland remained competitive against countries where grades of a similar quality are produced. "I think the employers mean business and they are not looking likely to submit."

Story by Andy Scott