"The deadlines are very short," Nowotny told Austrian radio Oe1. "It won't be easy, if you look at the situation on the capital markets at the moment." Austria's biggest banks -- Raiffeisen International, Erste Bank and Volksbank (OeVAG) -- will need to raise some 2.9 billion euros ($4.1 billion) if they are to increase their core Tier 1 capital ratio to 9.0 percent of assets, as agreed in late-night talks Brussels, according to Finance Minister Maria Fekter. Austrian financial regulator FMA said Thursday this was "do-able." State aid will always be available as back-up but the banks should not need to resort to it, FMA chief Helmut Ettl told Austrian television ORF. "I believe the banks will be able to raise this capital and not have to draw on state aid," he said. The Austrian banks will now have to submit a strategy before the end of the year explaining how they plan to find the necessary capital, Fekter said Thursday. Raiffeisen announced it will need 1.9 billion euros to reach the minimum capital level agreed by European leaders to enable banks to withstand potential losses on their holdings of eurozone governments' debt. OeVAG will require 972 million euros and Erste Group 59 million euros.