(Adds comments from BDI industry association)
BERLIN, Jan 4 (Reuters) - Protests in Iran are currently having no impact on trade ties with Germany, German engineering association VDMA said on Thursday.
It added, however, that it was unclear whether demand from Iran for German machinery would slow in the coming months.
Existing contracts from Iran were being completed, it said.
"At present, it is not possible to conclusively assess whether Iranian business is reducing or deferring its investments due to the domestic political situation," VDMA trade expert Ulrich Ackermann said.
The protests in Iran, which began last week over economic hardships suffered by the young and working class, have evolved into a rising against the powers and privileges of a remote elite, especially supreme leader Ayatollah Ali Khamenei.
Germany's largest industry group BDI appealed for calm, noting that the country's exports to Iran rose to 3.5 billion euros ($4.22 billion) in 2017 from 2.6 billion in 2016.
"The current wave of demonstrations show that Iran has not yet sufficiently managed to make the positive effects of economic development felt by the broad mass of the population," BDI head Joachim Lang said in a statement.
"To reach this goal, the conditions for economic engagement in Iran must further improve. U.S. President Donald Trump suggesting the prospect of new sanctions increases the uncertainty of German companies." ($1 = 0.8290 euros) (Reporting by Michael Nienaber and Emma Thomasson; Editing by Paul Carrel/Jeremy Gaunt)