(Adds strike plans from paragraph four, Schroeder interview)
By Katie Allen
BERLIN, Jan 30 (Reuters) - Germany's largest industrial union, IG Metall, staged short strikes across the country on Friday and called on 51,000 workers to leave work early in a mass walkout to pressure employers over pay and working hours.
IG Metall said short stoppages on Thursday had been stepped up to whole-day walkouts at some firms on Friday and that tens of thousands of engineering workers had downed tools and started their weekend early.
Carmakers DaimlerChrysler AG and Audi said they had been hit by the action. The union said it would also affect auto components groups Kolbenschmidt Pierburg and Robert Bosch [ROBG.UL].
IG Metall said later on Friday some of its members in more than 40 companies in central Germany would stage short strikes on Monday.
In northern Hesse, 6,000 workers from 23 companies plan to stop work and 400 workers in two firms in the eastern state of Thuringia planned to strike Sunday evening, the union said. Although the stoppages have targeted some major firms, particularly in the key automobile sector, analysts say the short walkouts, a typical feature of German pay talks, will cause little pain.
"While the strikes could hurt sentiment on the stocks, the medium-term earnings impact of warning strikes is negligible. Overall, in a still weak economic situation the risk of a prolonged strike is rather limited," said analysts at one bank.
The IG Metall walkouts come after the union said it could not accept employer demands for longer working hours and an offer well below the four percent pay rise it is claiming for 3.5 million engineering workers.
In the state of Bavaria, where carmaker BMW and industrial giant Siemens are based, IG Metall said it would ask between 50,000 and 100,000 workers to walk out next Friday if employers do not present a new offer on Thursday.
FIRST ALL-DAY WALKOUTS
In the central town of Stadthagen all-day strikes started at 0430 GMT at various firms, including elevator maker Otis , a union spokesman said.
IG Metall spokeswoman Martina Helmerich said the stoppages would spread next week in defiance of claims the union's power had waned as a result of falling membership and a failed strike over working hours last year.
"The warning strikes so far have been successful and we see them as a signal that we are able to mobilise people. But we still want to get a result through talks," she said.
Talks in Baden-Wuerttemberg, which traditionally leads pay negotiations for the rest of Germany, are scheduled to resume next Thursday, February 5.
An economic advisor to the government, Wolfgang Franz, said the union should move on from its old "ritual" of short strikes and suggested both parties enter talks without making their offers and demands public. That way no-one would lose face.
"Then neither side would have to resort to these campaign means to prove to people at the grass roots it's the best they could do," he told Die Welt daily. He said the final pay rise should be no more than two percent.
The government has also urged IG Metall to accept a moderate wage rise this year to help bring down stubbornly high unemployment. One in 10 Germans is unemployed.
Chancellor Gerhard Schroeder, in a television interview to be aired on Friday evening, urged unions and employers to seal an accord that "supports the economic recovery" and "especially helps small and medium-sized companies to become more competitive or to remain competitive."
IG Metall this week dismissed as a "provocation" an offer from employers for two pay rises of 1.2 percent each over 27 months and a demand for more flexible contracts so firms can vary working hours to match demand.
Under negotiating rules, IG Metall is allowed to stage short strikes to pressure employers during talks, provided the union gives the firms affected a clear start and end time. (Additional reporting by Madeline Chambers in Frankfurt)