Two major German employers' lobby groups called on Friday for workers to be banned from smoking cigarettes during work hours, saying it harmed productivity and cost firms money.

Mario Ohoven, president of the BVMW association of German medium-sized firms, told the Bild daily: "We've got to put an end to lighting up during work hours.

"Cigarette breaks cost firms money and disrupt the flow of the working day," added Ohoven, in an appeal that made the front page of Germany's most-read newspaper.

Another entrepreneur, Ursula Frerichs, from the UMW association of mid-sized businesses, said: "Additional breaks for smokers should be banned. Non-smokers should not be put at a disadvantage."

But the call ran into immediate opposition.

Such an initiative "would hardly contribute to a good atmosphere in companies," said Martina Perreng from the DGB trade union federation.

Around one-quarter of Germans are smokers -- about average for the European Union according to Eurostat figures -- and the tobacco lobby has a strong influence in the country.

The last of Germany's 16 states made lighting up in bars and restaurants largely illegal from July 2008, driving many smokers out of pubs.

However, the law was riddled with loopholes and many pub owners managed to circumvent it.