European banks are considering adopting detailed US-style disclosures of how they value financial instruments, going above and beyond the actual accounting requirements in a bid to help calm jittery investors.

Bank shares have tumbled in recent months as investors shied away from the sector because of uncertainties about the exact level of losses they faced. Most leading institutions are preparing their year-end results – the most detailed communication they have with shareholders – and are under pressure to provide as much disclosure as possible.