Bankia, one of the Spanish cajas forced by the government to shore up its capital buffers, has started an initial public offering that values the savings bank at a multiple as low as those applied to the troubled Greek and Irish banks.

In its prospectus, filed last night in Madrid, the lender values its shares at between 0.3 and 0.35 times its book value, giving the bank a market capitalisation of between €7.6bn and €8.7bn.