The pan-European STOXX 600 index fell 0.9% by 0809 GMT, but a sharp recovery earlier this week put it on track for weekly gains.
Shares of Credit Suisse AG and UBS Group AG fell 6.4% and 6.3%, respectively, after Bloomberg News
reported they are among the banks under scrutiny in a U.S.
Department of Justice (DOJ) probe into whether financial
professionals helped Russian oligarchs evade sanctions.
Austria's Raiffeisen Bank International slipped
1.8% after Reuters reported the European Central Bank is
pressing the bank to unwind its highly profitable business in
Russia.
Overall, European banks fell 2.3%, with Deutsche
Bank down 5.4% after a sharp jump in the cost of
insuring against the risk of default late the day before.
Financial services shares were down 1.5%.
Flash readings of S&P Global's March business activity for
the euro zone and UK will be released later in the day.
(Reporting by Sruthi Shankar in Bengaluru; editing by Eileen
Soreng)