Moody’s Investors Service continues to adjust its ratings on residential mortgage-backed securities to reflect updated loss expectations on pools issued between 2005 and 2007 — leading to ratings action on nearly $22 billion of RMBS. The New York-based ratings service said the changes reflect the “continued performance deterioration in subprime pools in conjunction with home price and unemployment conditions that remain under duress.” Most of the collateral backing the deals consists of first-lien, fixed or adjustable-rate subprime residential mortgages. One Moody’s analyst said Monday that many of the affected tranches have been on review since at least the first quarter of this year and the changes simply reflect the agency’s most-recent analysis. The agency downgraded 67 tranches, confirmed ratings of 15 tranches, and upgraded two tranches from 16 RMBS transactions worth $4.7 billion issued by HASCO. Moody’s downgraded 54 tranches of Alt-A RMBS worth $4 billion issued by Countrywide across 11 transactions in 2006 and 2007. The ratings of another $4 billion of Alt-A RMBS issued by Countrywide also were changed with 126 tranches getting downgraded, 39 receiving a confirmation, and four being upgraded. Analysts downgraded 59 tranches of subprime RMBS valued at $3.1 billion issued by Renaissance in 11 transactions. And $2.2 billion of RMBS issued by Nomura in 40 tranches over 10 transactions also was downgraded. Twelve tranches worth $1.45 billion from three RMBS transactions issued by Option One were downgraded. The ratings of 12 tranches issued by Newcastle in two RMBS transactions valued at $1bn were downgraded, and Moody’s downgraded 17 tranches worth $785 million from six RMBS transactions issued by Aegis and three tranches issued by ResMae worth $131 million. Five tranches of RMBS worth $585 million issued by Long Beach and WaMu across five transactions were downgraded. Write to Jason Philyaw.