The continent-wide STOXX 600 index dropped 1.5% by 0714 GMT, set to wipe out weekly gains.
European banks slid 2.4%, with shares of Deutsche Bank, Barclays and BNP Paribas leading declines.
The U.S. regional banks index dropped 6.3% on Thursday after announcements from two lenders fuelled investor unease about hidden credit stress.
Among other early movers, Novo Nordisk fell 4.6% after U.S. President Donald Trump said that the price of Danish drugmaker’s best-selling weight-loss drug would be lowered and that negotiations over price changes would be swift.
Spain’s BBVA jumped 7% after the lender failed to convince Sabadell shareholders to back its 16.32 billion euro ($19.07 billion) hostile takeover bid. BBVA said it would immediately resume shareholder remuneration.Shares of Sabadell fell 7%.