German engineering giant Siemens says its third-quarter profit is down slightly and predicted a complex year, citing "geopolitical tensions".

Net income stood at 1.38 billion euros ($A2.08 billion), down two per cent year on year for April to June, the Munich-based company said. Siemens, whose products include trains, gas turbines and medical equipment, confirmed its full-year outlook of an industrial business profit margin of 10 to 11 per cent….