Some euro zone banks have insufficient liquidity and several will continue to require support from the European Central Bank after long-term funding help runs out at the start of next year, credit ratings agency S&P said.
S&P said refinancing risks were lessening for Europe's banks as they improve their liquidity in the wake of the financial crisis, but they remain a considerable risk for some.
Its annual assessment of funding and liquidity at Europe's top 50 banks - including Bank of Ireland and AIB and based on 2013 data - found it was a weakness for the credit ratings at seven banks, a neutral factor for 41 lenders, and a strength for two banks.
"We believe that only a few banks have significant buffers to protect themselves against adverse market conditions," S&P said in its report.
It said liquidity and funding was a rating weakness for three banks in Greece - Alpha Bank, Piraeus and National Bank of Greece.
Spain's Bankia and Banco Popular Espanol, Dexia Credit Local and Portugal's Banco Espirito Santo were also facing that issue.
Several of those banks have improved their liquidity and funding positions this year.
BES, for example, has been overhauled, with healthy parts put into a new entity - Novo Banco - and recapitalised, with the aim of leaving the bank with strong enough capital ratios to fund itself.
S&P said it expected several euro zone banks will continue to require liquidity support when the ECB's long-term refinancing operations (LTRO), which started in late-2011 and early 2012, mature in January and February 2015.
"We therefore consider the ECB's ongoing commitment to conduct refinancing operations with full allotment at least until the end of 2016 a critical stabilising factor in case market sentiment deteriorates sharply," S&P said.
Banks have been steadily repaying the LTRO, and the ECB is offering about €400 billion of cheap cash under a new plan (TLTRO) to encourage lending.
S&P said it considered liquidity and funding as a positive on ratings for Standard Chartered and the German Cooperative Banking sector, helped by their strong retail deposit bases.