Fitch Ratings has assigned $28.8 million in MassHousing housing bonds a rating of ‘AA-,’ with a stable outlook, and affirmed the same rating on $1.5 billion in outstanding MassHousing bonds, citing the quasi-public state agency’s historically strong operating performance.

The ratings were given to the agency’s 2010 series B bonds and all outstanding MassHousing housing bonds under the general resolution. The 2010 series B bonds are expected to be sold through negotiation this week and close on or about June 24, according to a statement.

"The ‘AA-‘ rating reflects the sound credit quality of the loan portfolio and the overcollateralization of the bonds currently at 113 percent asset parity as of June 30, 2009, as well as cash flow surpluses sufficient to offset potential cash flow interruptions from future loan payment delinquencies, adequate legal provisions of the resolution, and MassHousing’s strong programmatic oversight capabilities," Fitch said.