The pan-European STOXX 600 benchmark index fell 0.1 percent with most country indexes also hovering around neutral.

Tuesday's US mid-term elections also kept traders cautious, as did uncertainty over whether renewed hopes of a breakthrough in Brexit negotiations were misplaced.

Results from the European banking stress tests had little impact, with the sector ending down 0.4 percent.

"The results provide no surprises and we expect little market reaction," Jefferies analysts wrote.

Britain's Barclays and France's Societe Generale were among unexpected laggards in the health check but their shares were muted, ending down 0.5 percent and up 0.3 percent respectively.

The Italian banking index lost 1.6 percent, however, after Goldman Sachs downgraded BPER and Intesa Sanpaolo to "sell". Their shares fell 3.4 percent and 1.5 percent respectively.

Lloyd's of London underwriter Hiscox fell 5.7 percent after warning that growth could moderate over the rest of the year.

Telenet lost 5.4 percent after a rating downgrade from Bank of America Merrill Lynch.

Top faller on the STOXX 600 was Grenke, which dropped 9 percent after the company said it may not be able to sustain growth rates in its core leasing business.

The company later delayed the placement of a five-year bond.

Among positive trading updates was Dutch oil and gas storage firm Vopak, up 5 percent, and Siemens Healthineers , which rose 2.8 percent after forecasting higher earnings for next year.

French payments group Ingenico, which has attracted bid interest from banking company Natixis, jumped 3.9 percent after it named a new chief executive on Monday, on hopes that a new board could strike a deal.

Britain's Micro Focus was up 2 percent after it said it expected full-year revenue to come in towards the higher end of a weak outlook and announced the departure of its finance director for ITV after less than 12 months.