UPDATE 2-Strike threat looms as labour talks get under way in Germany

* Union demands 6 pct higher pay, right to shorter hours

* Employers reject demand for right to shorter hours

* Regional talks in Baden-Wuerttemberg due on Thursday

* Union IG Metall has threatened 24-hour strikes (Changes dateline, adds comment by company CEO)

BOEBLINGEN, Germany, Jan 11 (Reuters) - German labour bosses and industrial employers were at loggerheads as regional wage talks began on Thursday, amid industrial action and the threat of strikes that could halt production at hundreds of companies.

Emboldened by robust German economic growth and record low joblessness, the powerful union IG Metall is demanding 6 percent more pay for 3.9 million metals and engineering workers in the country.

It is also making its first major push for shorter working hours in more than three decades, demanding that workers gain the right to reduce their weekly hours to 28 from 35 to care for children or elderly or sick relatives and then return to full-time employment after two years.

Employers have so far offered 2 percent plus a one-off 200- euro ($239) payment in the first quarter. They have rejected demands for a shorter working week unless hours could be increased temporarily as well so as not to put output at risk.

"Mid-sized companies like ours are already suffering from a scarcity of skilled workers, that would just become worse" under IG Metall's proposal, Stefan Wolf, the chief executive of car parts maker ElringKlinger and head of regional employers' association Suedwestmetall, told Reuters.

But unions such as IG Metall say it is time for workers to get a bigger share of corporate profits and for companies to step up and take social responsibility as the country's economy grows at its fastest pace in six years.

"We expect employers to take a big step toward us," Roman Zitzelsberger, head of IG Metall in the southwestern state of Baden-Wuerttemberg said before talks started there on Thursday.

More than 76,000 workers at hundreds of metals and engineering companies took part in industrial action on Thursday to support IG Metall's wage claim, and the union has announced further walkouts for Friday.

Such industrial action is common in Germany before sector-wide pay negotiations, and similar walkouts took place in 2016 and 2015.

But Germany's biggest trade union has threatened to call for 24-hour walkouts if talks fail to make progress, harking back to seven weeks of strikes in 1984 that helped push through a shortening of the work week to 35 hours from 40 hours.

Negotiations for workers in Bavaria are due to resume on Jan. 15 and in North Rhine-Westphalia on Jan. 18.

($1 = 0.8365 euros) (Additional reporting by Michael Nienaber; Writing by Maria Sheahan; Editing by Catherine Evans)