Fitch Ratings has downgraded ten tranches from six Irish Residential mortgage-backed securities transactions.
It has affirmed a further 29 tranches of the remaining nine transactions.
The downgrades only affect Celtic 11, Emerald 4, Kildare, Pirus, Lansdowne 1 and 2, as many of the more recent transactions benefit from higher levels of credit enhancement.
The outlook on all tranches remains Negative due to the ongoing uncertainty surrounding the Irish mortgage market.
A full list of rating actions is available here.
In a statement, Fitch said that "although the wider Irish economy has shown resilience in the past year, the mortgage market has continued to exhibit weakness.
"This has been evidenced by an increasing trend of arrears, which are reaching double digits, and having an effect on the entire Irish RMBS universe, albeit with differing levels of severity.
"Additionally, despite the fact that Dublin has demonstrated mild resistance to house price depreciation in recent months, Irish house prices are currently 50% lower than their peak," it added.
