Following news of bigger than expected sub-prime losses at Citigroup Inc., and the departure of its CEO, Fitch Ratings has downgraded its credit ratings for Citigroup. As well, the rating outlook is negative, Fitch says.

The downgrade primarily reflects severe pressure in Citi’s capital markets business, Fitch says. In particular, sizable charges are likely for Citi’s exposure to U.S. subprime-related assets, including collateralized debt obligations and other exposures. Recently, prices of these instruments have come under further considerable pressure from end-third quarter-2007.

In its securities and banking business, Citi’s direct exposure to U.S. subprime-related assets totals US$55 billion, consisting of almost US$12 billion of exposure in its lending and structuring business as well as approximately US$43 billion of exposure to super senior tranches of CDOs backed by ABS. Citi currently estimates charges ranging from US$8 billion to over US$11 billion (pre-tax) for these exposures. However, charges could exceed these levels depending on the extent of the CDO market slide, the rating agency observes. Potential write downs will depend on the vintage and asset types underlying the CDO exposures.

In addition, Citi and its U.S. peers face an inhospitable consumer credit environment marked by accelerating delinquencies, particularly in housing-related exposures, Fitch adds. Further, Citi’s exposures to leveraged finance transactions, subprime consumer mortgages, structured investment vehicles and conduits are concerns. These exposures appear manageable, but taken together exert significant incremental pressure on Citi’s finances, it notes.

The departures of the CEO and other senior managers inject additional uncertainties at a time when Citi faces multiple risk issues as well as integration of recent acquisitions. Any potential change in strategic direction under new leadership layers on more uncertainty, it says.

Given the likely magnitude of charges, Fitch expects a continuance of depressed results in the fourth quarter and perhaps beyond.