OREANDA-NEWS. December 15, 2015. Fitch Ratings has upgraded one and downgraded one class of Credit Suisse First Boston Mortgage Securities Corp. series 2001-CP4. A detailed list of rating actions follows at the end of this press release.

KEY RATING DRIVERS

The upgrade of class E to 'AAAsf' reflects the class being fully covered by defeasance as a result of recent loan payoffs. Currently, there are only two classes remaining in the transaction, collateralized by four remaining loans in the pool, two of which (24.7%) are defeased. The transaction had a significant principal paydown on the November 2015 distribution date, primarily due to the discounted payoff of the former largest two loans in the pool, the Somerset Center & Somerset Place, as well as Somerset Park. The proceeds were sufficient to pay off class D and partially pay down class E. Losses were applied to classes G and F.

Since Fitch's last rating action, the transaction has paid down \\$21.6 million and incurred additional realized losses of \\$8 million. Since issuance, the transaction has incurred realized losses of 9.4% of the original balance. Classes G through O have been completely depleted, and class F has experienced realized losses.

As of the November 2015 distribution date, the pool's aggregate principal balance has been reduced by 99% to \\$12.2 million from \\$1.18 billion at issuance. Interest shortfalls totaling \\$9.2 million are currently affecting classes H through O. The entire principal balance on class A is fully covered by the defeased loans, which mature in 2016.

The first remaining non-defeased loan in the pool is the Chevy Chase Bank loan (61.2% of the pool), which is secured by a 150,000 square foot (sf) office property located in Laurel, MD. It is 100% occupied by Capital One until 2020. The loan matures in August 2016. The loan continues to perform to expectations with a servicer reported year-end 2014 debt service coverage ratio (DSCR) of 2.05x, compared to 1.46x at issuance.

The second remaining non-defeased loan is the Airport Landing Apartment loan (37.6%), which is secured by a 240 unit multifamily property located in Houston, TX. As of June 2015, the property was 95% occupied, compared to 92% at issuance. The loan matures in June 2021. The loan is performing with the servicer reported second quarter (2Q15 DSCR at 1.78x, compared to 1.54x at issuance.

RATING SENSITIVITIES
The rating on class E is anticipated to remain stable. The class is expected to pay off upon maturity of the defeased loans. The distressed class F will remain at 'Dsf' due to realized losses.

Fitch has upgraded the following class as indicated:

--\\$0.9 million class E to 'AAAsf' from 'CCCsf'; Outlook Stable Assigned.

Fitch has downgraded the following class as indicated:

--\\$11.3 million class F to 'Dsf' from 'CC'; RE 0%.

Fitch has affirmed the following the following classes as indicated:

--\\$0 class G at 'Dsf', RE 0%;
--\\$0 class H at 'Dsf', RE 0%;
--\\$0 class J at 'Dsf', RE 0%;
--\\$0 class K at 'Dsf', RE 0%;
--\\$0 class L at 'Dsf', RE 0%;
--\\$0 class M at 'Dsf', RE 0%;
--\\$0 class N at 'Dsf', RE 0%.

Classes A-1, A-2, A-3, A-4, B, C, D and A-CP have paid in full. Fitch does not rate the class O certificates. Fitch previously withdrew the rating on the interest-only class A-X certificates.