Most of Europe's largest banks increased their fully loaded common equity Tier 1 ratios in the final quarter of 2019, according to data from S&P Global Market Intelligence.

The bank with the largest drop in the sample, Finland's OP Financial Ltd., reported a relatively small 10-basis-point decline quarter over quarter in its CET1 ratio but it still topped the list in absolute terms with the highest ratio of 19.50% at the end of December.

Sweden's Skandinaviska Enskilda Banken AB posted the biggest increase in the ratio, with a 124 basis point rise from the end of the third quarter to 17.59%.

On a year-over-year basis, U.K.-based Lloyds Banking Group PLC saw the largest decline, with its CET1 ratio dropping 102 basis points to 13.30% at the end of the fourth quarter, while Italy's Banco BPM SpA reported the biggest increase from a year prior, rising 280 basis points to 12.80%.

Spain-based Banco Santander SA ranked last in absolute terms in the fourth quarter of 2019, with a ratio of 11.41% despite a 35 basis point increase in its ratio during that period.

The ratio quantifies a bank's CET1 capital as a percentage of risk-weighted assets, and banks in the region must have a fully loaded CET1 ratio of at least 7% from 2019 onward under Basel III regulations, comprising a minimum 4.5% CET1 ratio and a 2.5% capital conservation buffer.