The eurozone economy grew less than expected in the third quarter as the public mood turned darker, with signs of distress in Italy highlighting concerns that the bloc's third-ranked state is becoming one of its weakest links.

The data, suggesting the slowdown has further to run, will make uncomfortable reading for the European Central Bank as it moves towards ending in December the programme of asset purchases it introduced in 2015 to boost inflation and economic growth.

Economists said the quarterly growth dip to 0.2% from 0.4% in the second quarter was unlikely to change those plans, though it might push back the date of the ECB's first post-stimulus hike in interest rates.

"We expect the ECB to stick to its plans to end asset purchases this year, but the recent run of weak data suggests that the bank will stress that policy tightening will depend on the incoming figures," Jessica Hinds, economist at Capital Economics, said.

The preliminary flash GDP reading from European statistics office Eurostat, which sent the euro to an intraday low against the dollar, was worse than expected.

Economists polled by Reuters had expected a 0.4% rise in the 19 countries sharing the euro. The 0.2% reported was the lowest growth pace in more than four years.

Eurostat does not provide national data in its flash estimates, but figures from Italy's statistics agency ISTAT showed growth there stagnated in the third quarter, as the government pursues a war of words with Brussels over a 2019 budget draft that breaks EU rules.