FRANKFURT, Jan 10 (Reuters) - Powerful German union IG Metall said it would step up industrial action ahead of a round of negotiations with employers as it pushes for higher wages and the right to shorter hours for 3.9 million German workers.
"We have started with warning strikes and will widen them in the coming days," IG Metall chief Joerg Hofmann told German daily Passauer Neue Presse in an interview published on Wednesday.
Around 80,000 German industrial workers have taken action since the start of last week in support of IG Metall's wage claims, and further walkouts have been announced for Wednesday.
With the economy in robust health and unemployment at record lows, the country's biggest union is demanding an inflation-busting 6 percent pay hike this year.
It has also called for a right to reduce weekly hours to 28 from 35 and return to full-time employment after two years for shift workers and those who need to care for children or elderly relatives.
Employers have so far offered 2 percent plus a one-off 200 euro ($239) payment in the first quarter.
They have also rejected demands for a shorter work week unless there was an agreement allowing for temporary increases in working hours as well.
Under the current proposal, companies would need to hire part-time workers to make up for those who cut their hours, the head of regional employers' group Nordmetall said in an interview.
"Where am I supposed to find them in times when there's a lack of skilled workers?" Nico Fickinger told German radio station NDR Info.
($1 = 0.8377 euros) (Reporting by Maria Sheahan; Editing by Ludwig Burger)