National Bank of Greece, the country\'s largest lender, said Friday it suffered a 2011 net loss of 12.3 billion euros ($16 billion) after taking a huge charge on a sovereign debt writedown. It said the loss on the writedown -- agreed with private creditors as part of a second Greek debt bailout -- was 10.75 billion euros, to which were added other provisions and charges due to \"the extremely harsh economic climate in Greece.