European stocks fell, snapping four days of gains, after yesterday rising to their highest valuation since 2010, and as European Union leaders failed to discuss further aid for Spain.

Leaders committed to their goal of establishing a euro-area bank supervisor by the end of the year. The EU will seek to agree on a framework that makes the ECB the main supervisor by Jan. 1, according to conclusions released early today after leaders met. The new system, intended to break the link between banks and governments at the root of the region’s financial crisis, will phase in over the next year and could cover all 6,000 euro-area banks by Jan. 1, 2014, a year later than initially targeted.

Still, the move doesn’t settle the question of when the European Stability Mechanism will be able to recapitalize banks directly. The plan calls for the supervisor to take charge of big banks and bailed-out institutions first, while also saying direct assistance requires “effective” supervision in place.

German Chancellor Angela Merkel said after the summit that it’s an open question whether European policy makers can meet the deadline they’d set hours earlier to establish a euro-area bank supervisor.

FTSE 100 5,896.15 -20.90 -0.35%, CAC 40 3,504.56 -30.62 -0.87%, DAX 7,380.64 -56.59 -0.76%

STMicroelectronics NV, Europe’s largest semiconductor maker, fell 3.5 percent to 4.78 euros as Banco Santander SA cut its price estimated on the shares to 5.20 euros from 6.75 euros.

Valeo SA advanced 3 percent to 35.95 euros. France’s second-largest car-parts maker said third-quarter revenue rose 6.8 percent to 2.84 billion euros from 2.66 billion euros a year earlier as demand from emerging markets offset a declining car market in Europe.

Carrefour SA gained 5.9 percent to 18.36 euros. Cencosud SA, Chile’s biggest retailer by sales, agreed to buy Carrefour’s Colombian unit for 2 billion euros including debt.