The British pound meanwhile pushed higher, one day after Prime Minister Theresa May won a vital confidence vote that was sparked by her Brexit deal.
In late morning deals, London and Paris stock markets overturned opening gains to trade in negative territory but Frankfurt held firm.
The ECB will unveil its latest monetary policy decision at 1245 GMT.
The so-called guardian of the euro, headed by president Mario Draghi, is forecast to end the "quantitative easing" (QE) programmed that has seen it pump 2.6 trillion euros ($3.0 trillion) into the eurozone economy in order to stoke growth and inflation.
- End of QE? -
"Today sees markets turn to the ECB for directional guidance, with Mario Draghi expected to announce the end of asset purchases," said IG analyst Joshua Mahony.
"While the end of QE is widely expected, there is always a slight inkling that Draghi could throw a curveball and decide to hold off given the current political and economic instability throughout Europe.
"With growth and inflation widely expected to be revised down, the bullish outlook is likely to be tempered somewhat, yet whether this will be enough to change the current course is another matter."
The ECB originally began buying debt in 2015, saying it wanted to fight the threat of deflation and keep money flowing around the eurozone economy.
Growth has picked up since then, surging in 2017 before falling back this year, but forecasts see inflation falling short of the central bank's target of close to, but below 2.0 percent.
"The euro will be under the spotlight as the ECB meet," noted London Capital Group analyst Jasper Lawler.
"Four years ago the ECB started buying up bonds on a massive scale to overcome economic stagnation. Last year the eurozone achieved the fastest pace of economic growth since the financial crisis.
"However, concerns are growing that eurozone economic growth is losing momentum."
- Asia stocks rally -
Asia meanwhile enjoyed more gains Thursday as investors are cheered by the more conciliatory noises from China and the US on trade.
While the tariffs row between Beijing and Washington is far from being resolved, there is a lot more optimism on trading floors this week that the world's top two economies can make headway in talks over the next three Reuters
Dealers mulled a report that Beijing is considering replacing its "Made in China 2025" programmed that aims to boost its technology sector, a key point in anger for Washington.
The Wall Street Journal said authorities were looking at putting back the scheme's timetable by a decade to concentrate on improving standards.
That followed news China had agreed to resume importing soybeans -- a major boost for US farmers -- as well as remove a levy on US autos imposed earlier this year in response to Donald Trump's initial tariffs.
Sterling was not far from 20-month lows but held on to Wednesday's gains of more than one percent that came in reaction to Prime Minister Theresa May winning a no-confidence vote by her ruling Conservative party.
- Key figures around 1115 GMT -
London - FTSE 100: FLAT at 6,878.50 points
Frankfurt - DAX 30: FLAT at 10,930.59
Paris - CAC 40: DOWN 0.1 percent at 4,906.92
EURO STOXX 50: UP 0.1 percent at 3,112.16
Tokyo - Nikkei 225: UP 1.0 percent at 21,816.19 (close)
Hong Kong - Hang Seng: UP 1.29 percent at 26,524.35 (close)
Shanghai - Composite: UP 1.2 percent at 2,634.09 (close)
New York - Dow Jones: UP 0.6 percent at 24,527.27 (close)
Pound/dollar: UP at $1.2657 from $1.2629 at 2200 GMT
Euro/dollar: UP at $1.1372 from $1.1369
Dollar/yen: UP at 113.48 yen from 113.29 yen
Oil - Brent Crude: DOWN 19 cents at $59.96 per barrel
Oil - West Texas Intermediate DOWN 18 cents at $50.97