Trading volume in Commerzbank stood at more than twice its 90-day daily average.
"We're well overdue a bit of a sell-off... you've also got some very disappointing results from Commerzbank this morning which have basically fed into the banking sector," Michael Hewson, senior markets analyst at CMC Markets, said.
European auto stocks also came under pressure, off 3.2 percent after gains left investors such as Citi and HSBC sifting through the sector for companies that still offer some value.
The auto sector was the best performer in Europe in 2012, surging 38 percent, and since September it has rallied around 20 percent, despite continued earnings per share downgrades.
Over the last six months I/B/E/S 12-month forward earnings per share forecasts have been downgraded by 12 percent as European car market fundamentals have deteriorated further.
HSBC said French car makers face major challenges and downgraded Renault to "neutral" from "overweight" after a strong share price run that has raised it 32 percent since mid November.
Renault fell 3.3 percent.