KBW analyst Diane Merdian now estimates Citigroup (C) will take $15.3 billion in writedowns in the fourth quarter tied to mortgage-backed debt and collateralized debt obligations, instead of the $11 billion previously estimated, according to a report from The Associated Press.

Citi shares are down 1.2% to $28.52 which will put them at a new 52-week low.

Douglas A. McIntyre