The pan-European STOXX 600 <.STOXX> index ended up 0.2 percent, gaining pace after a sluggish opening as banking stocks headed higher. Germany's DAX <.GDAXI> was up 0.3 percent while euro zone blue chips <.STOXX50E> gained 0.5 percent.

European tech firms <.SX8P> were standout performers, with the sector up 1.4 percent after shares in Nokia (>> Nokia Oyj) jumped 6.4 percent to their highest since February 2016 following the settlement of a patent dispute with Apple (>> Apple Inc.).

Positive economic data also supported sentiment, with PMI surveys for May showing businesses across the euro zone kept up April's impressive growth rate.

"It's a kind of risk-on environment, and Europe's benefits - relatively low currency, a relatively attractive valuation against the United States and many other regions, and of course being a developed market - should enable it to continue to outperform," Ken Odeluga, market analyst at City Index, said.

Upgrades also helped the top STOXX gainers, with Banco BPM (>> Banco BPM SpA) rising 5.9 percent after Barclays upgraded the Italian lender to "overweight" from "equal weight".

Analysts at Barclays cited Banco BPM's attractive valuation compared to Italian peers as well as progress with its portfolio of bad loans.

"Banco BPM has much work to do reducing its NPLs and also raising its coverage ... yet management has made a good start in 1Q17," analysts at Barclays said in a note, referring to Banco BPM's non-performing loans.

Overall banking stocks <.SX7P> gained 0.8 percent, with shares in Spanish banks Banco de Sabadell (>> Banco de Sabadell SA), Santander (>> Banco Santander, S.A.) and BBVA (>> Banco Bilbao Vizcaya Argentaria S.A.) regaining losses from the previous session when they were hit by political worries after Spain's Socialists re-elected hardliner Pedro Sanchez.

Spain's IBEX <.IBEX> gained 1.1 percent.

Among other regional benchmarks, Greece's ATG index <.ATG> fell after euro zone finance ministers failed to agree debt relief for Athens with the International Monetary Fund and did not release new loans.

In Britain, the FTSE 100 <.FTSE> ended down 0.15 percent.

Campaigning ahead of the June 8 general election was suspended after at least 22 people, including some children, were killed in a suicide bomb attack in Manchester overnight.

There was little direct market impact seen from the attack, although shares of theme park operator Merlin Entertainments (>> Merlin Entertainments PLC) fell 1.5 percent.

(Additional reporting by Danilo Masoni; Editing by Ed Osmond and David Evans)

By Kit Rees