The European Central Bank had intended to bring to an end most of its support for the banking system by the middle of this year, but those plans were thwarted by the sovereign credit issues faced by Greece and the ripples that have hit other countries in the region.

Fabio Lisanti, co-head of debt capital markets for Europe at UBS, said: "The ECB will remain crucial for financial sector funding as there are strains in some areas of the debt capital markets.