Finnish cellphone maker Nokia Corp. (NOK) could face disruption from strike action Monday if unions follow through with a threat to widen their action over stalled wage talks.

Labor unions the Federation of professional and managerial staff, YTN, and the Association of IT sector employees have been on strike since Tuesday involving some 10,000 white-collar managerial employees in about 40 Finnish companies.

Among the companies affected are elevator maker Kone Oyj (KNEBV.HE), industrial crane maker Konecranes Oyj (KCR1V.HE), steel firm Rautaruukki Oyj (RTRKS.HE), engine maker Wartsila Oyj (WRT1V.HE), and Swedish miner Boliden AB's (BOL.SK) Finnish operations.

If a deal isn't reached by Monday, the strike will widen to cover about 25,000 white-collar employees, from 0400 GMT, labor union YTN said. That will include Nokia employees for the first time.

Nokia, the world's largest handset maker by volumes, has about 18,600 employees in Finland.

Asked about the consequences, Nokia spokesman James Etheridge said it was too was too early to speculate, but that it wouldn't affect Nokia's 3,700 production personnel at its mobile handset manufacturing plant in Salo, Finland.

The unions are demanding compensation for work-related travel outside of working hours.

The Federation of Finnish Technology Industries condemned the strike and said it jars with the uncertain and deteriorating economic outlook.

The YTN union has been operating an overtime ban involving about 200,000 workers since Oct. 4.

-By Arild Moen, Dow Jones Newswires; +358-9-2516 6279; arild.moen@dowjones.com