The pan-European STOXX 600 <.STOXX> index fell 0.2 percent, after hitting a 20-month high in the previous session. France's CAC <.FCHI> fell 0.3 percent, off Wednesday's nine-year high.

The ECB kept its ultra-easy policy stance in place as inflation continues to undershoot its target but explicitly acknowledged the vigour of the euro zone economy, now on its best run since the global financial crisis.

The news conference by Mario Draghi saw equity indexes see-sawing but remarks from the central bank governor failed to provide a clear direction for markets.

"This was a pretty confusing and conflicting performance from Mr Draghi. He's had to acknowledge that the growth outlook has improved and the risks to the outlook are more balanced without following that through into the inflation outlook," said Aberdeen Asset Management investment manager James Athey.

"At this stage, it's better to just look beyond today. There's enough from today to suggest that we might see a material change in policy in June," he added in a note.

Besides the ECB, earnings were a key focus for equity traders in Europe. First-quarter earnings for STOXX 600 companies are expected to rise 5.5 percent and revenues are seen up 5.7 percent, according to Thomson Reuters I/B/E/S data.

Deutsche Bank (>> Deutsche Bank AG) shares fell 3.7 percent as a fall in first-quarter revenues disappointed, even though net profit more than doubled due to a rebound in bond trading.

"We are positive on costs and capital but the key uncertainty remains revenues," said UBS analysts.

Deutsche Bank's share price has nearly doubled from its September 2016 lows.

A 6 percent drop in Spain's Banco Popular (>> Banco Popular Espanol SA) added to underperformance in euro zone banks <.SX7E>, down 1.8 percent. Intesa Sanpaolo (>> Intesa Sanpaolo SpA) also weighed, down 2.3 percent, after Generali (>> Assicurazioni Generali SpA) said it saw a short term opportunity to sell its stake in the Italian lender.

However, results from Lloyds (>> Lloyds Banking Group PLC) boosted the British bank by 2.3 percent after its first-quarter profit bucked expectations of a post-Brexit dip.

First-quarter earnings hit by weak margins in its renewable and retail business dampened appetite for shares in Finnish energy company Neste (>> Neste Oyj) which fell 4.2 percent, dragging on the broader European energy index.

Shares in debt-laden aeronautical firm Zodiac Aerospace (>> Zodiac Aerospace) fell 6.5 percent after a French media report raised doubts on a planned takeover by Safran (>> SAFRAN).

"Zodiac being acquired by Safran would actually be the best thing to happen for Zodiac shareholders," said Alphavalue analysts in a note, adding that its "dangerously" high level of debt would require a capital increase of 0.7 billion euros.

Among risers, Mediclinic (>> Mediclinic International PLC) jumped 17.5 percent after Abu Dhabi cancelled a requirement for citizens to make a 20 percent co-payment for treatment at private facilities, in a boon to private healthcare providers.

Elsewhere, upbeat results from the likes of SKF (>> AB SKF) , Nokia (>> Nokia Oyj) and Subsea 7 (>> Subsea 7 SA) were cheered as more investors piled into the European economic recovery story.

Of the 20 percent of STOXX companies having reported so far, 70 percent had beaten estimates while 19 percent had missed, Thomson Reuters data showed.

(Reporting by Danilo Masoni; Editing by Mark Trevelyan)

By Danilo Masoni and Helen Reid