A couple of articles regarding the amount of capital required by Greek banks generally (not NBG specific)
http://pragcap.com/credit-update-schedule-chicken
http://www.reuters.com/article/2012/02/27/greece-moodys-banks-idUSL5E8DR5LD20120227
"Bond swap to wipe out Greek bank capital base-Moody's"
http://pragcap.com/credit-update-schedule-chicken
http://www.reuters.com/article/2012/02/27/greece-moodys-banks-idUSL5E8DR5LD20120227
"Bond swap to wipe out Greek bank capital base-Moody's"