Europe ends in the red as miners, banks slide; ECB, OPEC in focus

European stocks finished in the red on Wednesday as sharp declines from European banks and miners weighed on sentiment, ahead of a number of key policy events due out later this week.

The pan-European STOXX 600 ended down around 1 percent provisionally, with almost all major sectors posting strong losses by the close.

One key data point markets have been digesting on Wednesday is China's latest PMI data. The official PMI came in at 50.1 for May, steady with April's level and a tick above a Reuters poll forecast for 50.0. The 50-point mark separates expansion from contraction.

However, other readings of China's manufacturing and services sectors sent a less convincing message. The Caixin/Markit manufacturing PMI index, which tracks small and medium-sized enterprises, slipped to 49.2 in May. The mixed data signals caused most major Asian markets to close lower, and added pressure to the mining-heavy FTSE 100 index.

The basic resources sector was Europe's worst performer on Wednesday as a result of a stronger dollar, mixed metal prices and the China data. Rio Tinto shares tumbled, closing down 3.8 percent, with BHP Billiton, Glencore and Antofagasta all finishing sharply lower.

Investors are also keeping an eye on oil ahead of an OPEC meeting that takes place on Thursday, in Vienna. Oil prices and stocks were in the red on Wednesday, as concerns around China's economy and the Middle East's production output added pressure to the markets.

However, both Brent and U.S. crude came off session lows by Europe's close, after four OPEC sources said the producer group would consider a new oil output ceiling at this week's meeting, according to Reuters.

And the European Central Bank's (ECB) meeting on Thursday was also closely-watched. Investors will be looking to see if the ECB changes its inflation forecast and gives any hints about further monetary policy moves.

In peripheral markets, Spain's IBEX 35 was one of the worst performing bourses, closing 1.3 percent down. This comes after Markit data showed that the growth of Spain's manufacturing sector had slowed in May, coming in at 51.8, down from April's 53.5. For the euro zone as a whole, manufacturing PMI hit 51.5 in May, down from 51.7 in April.

Elsewhere, U.S. markets traded mostly lower at Europe's close, weighed down by concerns on sluggish global growth.

Italian banks came under pressure after a report in Il Messaggero said that the Bank of Italy could ask the country's lenders to put 1.5 billion euros ($1.67 billion) into the resolution fund. Investors are concerned about the bad loan portfolio of many of the Italian banks.

Veneto Banca also announced a price range of 0.1-0.5 euros per share for its upcoming 1 billion euro initial public offering. Due to low demand, the country's backstop fund - Atlante - has agreed to buy any unwanted shares. If Atlante steps in, it would be the second time it has taken action after it underwrote Banca Popolare di Vicenza's 1.5 billion rights issue.

BMPS, Banco Popolare and Banca Popolare di Milano were all off more than 3.5 percent each, by Europe's close.

On the earnings front, supermarket operator Ahold reported a 4.3 percent rise in net sales for the first quarter of the year and said its proposed merger with Delhaize is "on track to close in mid-2016". Ahold shares popped 2.5 percent, making it a top performer. Delhaize shares also jumped over 2 percent.

Technicolor shares closed over 3 percent up. This comes after Morgan Stanley raised its price target and rating on the stock.

In the U.K., house price growth remained slow, up 0.2 percent month-on-month in May. British housebuilding names such as Persimmon, Berkeley Group and Taylor Wimpey all closed more than 2.5 percent down.

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