The shares fell 27 per cent in morning trade to €1.21 in an initial reaction to reports in El Mundo, a national Spanish newspaper, that customers had withdrawn the large amount, citing information from a recent board meeting.

Spain’s stock market regulator placed the shares “under auction”, a process used to allow market participants to better cope with heavy trading volumes.

The bank later issued a regulatory filing, which said the evolution of deposits in the first half of May was seasonal.