Fitch is the only one of the three major U.S. credit rating agencies that was still reviewing MBIA's critical "AAA" ratings for a possible downgrade. It has also been faster than larger rivals Moody's Investors Service and Standard & Poor's to downgrade other bond insurers' ratings.
Williard Hill, a spokesman for MBIA, said Fitch's rating practices were "not at all" a factor in the withdrawal request. MBIA did ask Fitch to continue rating more than $1.1 billion of unsecured debt issued by the company.
MBIA said in a statement that Fitch's rating process "differs in many significant respects from those of the other rating agencies, which affects how investors assess value."
"In turbulent times, the impact of this difference becomes significant, raising the risk of misinterpretation," MBIA added.
Fitch responded on Friday, saying that it was disappointed with MBIA's request as well as the criticism of its analysis and fees.
"Our analysis is of the highest quality and our understanding of MBIA's municipal and structured exposure is very strong," Stephen Joynt, president and CEO at Fitch said in a statement.