FRANKFURT (Reuters) - The European Central Bank lowered slightly its 2017 economic growth and inflation forecasts on Thursday and predicted that price growth would remain below its target through 2018 despite extraordinary stimulus.

The ECB cut its 2017 growth forecast to 1.6 percent from 1.7 percent seen in June, to account for risks including the expected effect of Britain's decision to leave the European Union, ECB President Mario Draghi said.

Inflation has undershot the ECB's target for more than three years and is expected to stay below target for years to come as growth remains weak, unemployment hovers near 10 percent and the economy struggles with large slack.

(Reporting by Balazs Koranyi; Editing by Catherine Evans)