Spain’s troubled banks could need as much as €62bn in new capital, independent auditors have calculated.

Moody’s Investors Service cut the long-term debt and deposit ratings of 16 Spanish banks yesterdays, including Banco Santander, the eurozone’s largest, saying the government’s ability to support some banks had weakened.

Spain drew solid demand for its debt yesterday, easily shifting what it wanted to sell at a bond auction, although concerns about Greece’s second bailout and the fragility of some of the eurozone’s riskier economies pushed financing costs higher.