For European banks, it's a headache that just won't go away: the944 billion euros (US$1.17 trillion) of non-performing loans thatare weighing down their balance sheets.

Economists say the pile of past-due and delinquent debt makes itharder for banks to lend more money, hurting their earnings.European authorities are prodding lenders to sell or wind downnon-performing credit, but they're split on how to tackle theissue, and some investors are disappointed by the paceof progress.

There are various ways of calculating soured loans. The EuropeanCentral Bank (ECB) advises that non-performing asset indicatorsshould be interpreted with caution because the definition ofimpaired assets and loss provision differ between countries. Thedata used below refers to domestic banking groups and stand-alonebanks only, and excludes foreign subsidiaries and controlledbranches.