The EU's top 42 banks need a further €70.4B ($95B) of capital to comply with Basel III core-capital regulations, the European Banking Authority estimates.
By the end of last year, the combined gap had been cut by €29.1B compared with six months earlier.
The rules, which are due to come into effect in 2019, require that banks hold a core-capital buffer of at least 7% of their assets on a risk-weighted basis.
Banks will also need to maintain a leverage ratio of 3% of their total non risk-weighted assets from 2018. The shortfall for this requirement is €106.6B.