Credit ratings agency Moody's has said that European banks' energy exposure is "manageable" despite low commodity prices.
But it added that some cases could require additional provisions if oil prices remain "low for longer".
Brent crude has fallen from over $110 per barrel in June 2014 to around $40 today. This has heaped pressure on to energy companies' balance sheets, making it harder to meet their debt repayments.
Moody's found that 19 large European banks has total energy exposures of €270bn (£217bn) at the end of 2015, or about three per cent of the peer group's total loans.
Most of the their energy exposures are concentrated in the large integrated oil companies, which are considered less risky than exploration, production, transport or storage companies.
This is in contrast with US and Canadian banks, which have larger exposures to these lower-rated sectors.
“A prolonged oil price slump, which is in line with our expectations, would entail more provisions for the large European banks," Alessandro Roccati, Senior Vice President at Moody’s.
Any future losses from energy companies would eat into their profitability, which is already challenged by the weak operating environment."