Greece's top lender National Bank on Wednesday reported a net loss of 2.14 billion euros ($2.75 billion) for 2012 while Alpha Bank said it had sustained a net loss of 1.09 billion euros over the same period.
National Bank, which recently completed a merger with number two lender Eurobank, said total assets stood at 104.8 billion euros with deposits at 58.7 billion euros.
New number-two Alpha Bank, which acquired smaller lender Emporiki Bank from France's Credit Agricole, had 76.5 billion euros in assets and 41.4 billion euros in deposits.
Eurobank, in its final filing, reported an annual loss of 1.45 billion euros with impairment losses of over 1.65 billion euros.
Greek stocks tumbled for a second day on Wednesday, with the Athens stock exchange shedding 3.99 percent to 849.62 points on fear of contagion from the financial crisis in neighbouring Cyprus.
Bank shares in particular fell by 2.29 percent, with NBG losing 3.57 percent and Alpha down by 3.84 percent.
Greek banks last year sustained huge losses in a sovereign debt write-down worth more than 100 billion euros and a subsequent debt buy-back.
In 2011, NBG had lost over 12.3 billion euros, Alpha over 3.8 billion and Eurobank 5.5 billion.
The banks' recapitalisation is a condition for the continued release of EU-IMF rescue loans for Greece's crisis-hit economy.
A sum of 50 billion euros out of the total EU-IMF bailout fund of 240 billion euros has been earmarked for this purpose.
At least 10 percent of new capital must come from private investors to keep the banks from being effectively nationalised.
The recapitalisation process is expected to be completed in April, though the banks are hoping to postpone this deadline.