Siemens became one of the first large German industrial companies to bow to pressure from the German and US governments when the group announced on Tuesday it would seek no new business in Iran.  The move comes as a US and European push for new United Nations sanctions on Tehran continues to encounter obstacles. It also highlights the importance of Washington’s informal but intense drive to convince international groups to drop ties with Iran.

He said some contractual agreements still had to be fulfilled but “starting in the middle of 2010, we will take on no new orders from Iran”. Siemens had sales of €500m ($700m, £440m) in Iran last financial year, 0.7 per cent of total sales. By contrast, Siemens’ US business is a pillar of the group, with more than 70,000 of its 402,000 workforce employed in the country.

While Deutsche Bank and Commerzbank pulled out of Iran after earlier UN resolutions and the US’s accompanying lobbying campaign, German manufacturers have continued to do business there.

Daimler pulled out of Iran in 2007 – when it still owned US carmaker Chrysler and was under direct pressure from Washington – but no other big-name groups have since publicly followed suit.

“Siemens’ is a big step for German industry,” an industry official said. “The company has been trading with Iran for a generation, so it must have been a hard decision, taken with an eye on its US interests.”