ECB policymaker Francois Villeroy de Galhau said that lower capital requirements for European subsidiaries of EU banks would help encourage the emergence of more cross-border banks.

ECB officials have long called for cross-border consolidation among European banks, which they believe would help credit flow to countries needing it most, making their monetary policy more potent.

"We will not achieve an effective and profitable Banking Union without cross-border consolidation in Europe: there are still too many roadblocks and not enough cross-border restructuring," Villeroy said.