OREANDA-NEWS. Fitch Ratings has downgraded and removed two classes from rating watch negative, and affirmed four classes of Credit Suisse First Boston Mortgage Securities Corp. (CSMC), series 2009-RR4. A detailed list of rating actions follows at the end of this press release.

KEY RATING DRIVERS

The downgrades are due to Fitch downgrading the underlying CSMC 2007-C5 class A4 to 'Asf', Stable Outlook from 'AAAsf' Rating Watch Negative on April 9, 2015. Principal and interest from the underlying commercial mortgage-backed certificate is applied to the A4-A and A4-B certificates in sequential order, while losses are applied in reverse sequential order. As a re-securitization, the class will receive cash flows from the underlying class A4 bonds and the rating is based on the underlying security.

For additional information on the underlying security please see the release 'Fitch Downgrades 2 Classes of CSMC 2007-C5; Removed from Rating Watch Negative' (April 9, 2015) available at 'www.fitchratings.com'.

RATING SENSITIVITIES

Classes with Stable Outlooks reflect that no rating changes are anticipated as the classes have implied credit enhancement of approximately 50% and 60%. Downgrades are not expected unless there is a significant and unanticipated increase in expected losses. The Negative Outlook on class A4-B-A reflects the possibility of future downgrades if expected losses on specially serviced loans increase.

Fitch has downgraded the following classes:

--\$9,660,000* Class A4-B to 'Asf' from 'AAAsf'; Outlook Stable assigned;
--\$4,830,000** Class A4-B-B to 'Asf' from 'AAAsf' Outlook Stable assigned.

Additionally, Fitch affirms the following classes as follows:

--\$24,267,000* Class A4-A at 'AAAsf'; Outlook Stable;
--\$19,400,000** Class A4-A-A at 'AAAsf'; Outlook Stable;
--\$4,867,000** Class A4-A-B at 'AAAsf'; Outlook Stable;
--\$4,830,000** Class A4-B-A at'AAAsf'; Outlook Negative;

Prior to today's downgrades, classes A4-B and A4-B-B were on Rating Watch Negative.

*Exchangeable certificates
**Exchangeable REMIC certificates