Fitch Upgrades 15 & Affirms 35 RMBS Ratings from 8 MASTR Securitizations.

NEW YORK -- Fitch Ratings has taken rating actions on the following Mortgage Asset Securitization Transactions (MASTR) residential mortgage pass-through certificates:

MASTR Asset Backed Securities Trust, series 2002-NC1

-- Class M-1 upgraded to 'AAA' from 'AA';

-- Class M-2 upgraded to 'AA-' from 'A';

-- Class M-3 upgraded to 'A-' from 'BBB';

-- Class M-4 affirmed at 'BBB-'.

MASTR Asset Backed Securities Trust, series 2002-OPT1

-- Classes A-1 & A-2 affirmed at 'AAA';

-- Class M-1 upgraded to 'AAA' from 'AA+';

-- Class M-2 upgraded to 'AA+' from 'AA';

-- Class M-3 upgraded to 'AA-' from 'A';

-- Class M-4 upgraded to 'A-' from 'BBB+';

-- Class M-5 affirmed at 'BBB';

-- Class M-6 affirmed at 'BBB-'.

MASTR Asset Backed Securities Trust, series 2003-NC1

-- Class M-1 upgraded to 'AAA' from 'AA';

-- Class M-2 upgraded to 'AA' from 'A';

-- Class M-3 upgraded to 'AA-' from 'A';

-- Class M-4 upgraded to 'A+' from 'A-';

-- Class M-5 upgraded to 'A-' from 'BBB';

-- Class M-6 affirmed at 'BBB-'.

MASTR Asset Backed Securities Trust, series 2003-OPT1

-- Classes A-1 & A-2 affirmed at 'AAA';

-- Class M-1 upgraded to 'AA+' from 'AA';

-- Class M-2 upgraded to 'AA-' from 'A';

-- Class M-3 upgraded to 'A+' from 'BBB+';

-- Class M-4 affirmed at 'BBB';

-- Classes MF-5 & MV-5 affirmed at 'BBB-'.

MASTR Asset Backed Securities Trust, series 2003-OPT2

-- Classes A-1 through A-3 affirmed at 'AAA';

-- Class M-1 affirmed at 'AA';

-- Class M-2 affirmed at 'A';

-- Class M-3 affirmed at 'BBB+'

-- Class M-4 affirmed at 'BBB';

-- Class M-5 affirmed at 'BBB-'.

MASTR Asset Backed Securities Trust, series 2003-WMC2

-- Class M-1 affirmed at 'AA';

-- Class M-2 affirmed at 'A';

-- Class M-3 affirmed at 'A-';

-- Class M-4 affirmed at 'BBB+'

-- Class M-5 affirmed at 'BBB';

-- Class M-6 affirmed at 'BBB-'.

MASTR, Inc., series 2004-P7

-- Classes A-1 through A-7 affirmed at 'AAA'.

MASTR Seasoned Securitization Trust, series 2004-2

-- Classes A-1 through A-3 affirmed at 'AAA'.

The affirmations, affecting approximately $800 million of the outstanding certificates, reflect a stable relationship between credit enhancement and expected loss. The upgrades, affecting approximately $350 million of the outstanding certificates, are being taken as a result of low delinquencies and losses, as well as increased credit support levels.

Four of the above MASTR Asset Backed Securities Trust (MABS) transactions are failing their delinquency triggers (2002-NC1, 2002-OPT1, 2003-NC1, and 2003-OPT1) and Fitch believes they will continue to fail for life. As a result, the bonds will pay sequentially and, in the case of series 2002-NC1, 2003-NC1, and 2003-OPT1, the overcolleralization (OC) will step down. This has the effect of keeping the credit enhancement relatively high. All of the above MABS transactions are at target OC except for 2002-NC1. Even though its OC is missing target, it is still sufficiently high to support upgrades.

The collateral for the above MABS transactions primarily consists of conforming and non-conforming, fixed-rate and adjustable-rate subprime mortgage loans secured by first and second liens on residential properties. The mortgages underlying the 'NC' transactions were originated or purchased by New Century Mortgage Corp. and are serviced by Ocwen Financial Corp. (rated 'RPS2' by Fitch). The mortgages underlying the 'OPT' transactions were originated or purchased by Option One Mortgage Corp. and are serviced by Option One Mortgage Corp. (rated 'RPS1' by Fitch). In addition, over 60% of the mortgages in series 2003-OPT1 and 2003-OPT2 are covered by deep mortgage insurance policies provided by Radian Guaranty Inc. The mortgages underlying series 2003-WMC2 were originated by WMC, a mortgage banking company incorporated in the State of California. As of March 2000, WMC underwrites and processes 100% of its loans on the Internet via 'WMC Direct'. The mortgages are serviced by Chase Home Finance, LLC (rated 'RPS1' by Fitch).

MASTR 2004-P7 is a resecuritization of MASTR 2003-5, class 4-A-4 and ABN AMRO 2003-12, class 2-A both of which maintain an 'AAA' rating with Fitch. MASTR Seasoned Securitization Trust (MSSTR) 2004-2 is a resecuritization of MSSTR 2004-1, classes 2-A-1 through 2-A-4 and 2-A-6 all of which maintain an 'AAA' rating with Fitch.

The pool factors (i.e., current mortgage loans outstanding as a percentage of the initial pool) for the MABS transactions range from 14% (2002-NC1 & 2002-OPT1) to 20% (2003-OPT2) and the seasoning ranges from 28 months (2003-WMC2) to 39 months (2002-NC1). MASTR 2004-P7 has a pool factor of 69% and is seasoned 20 months. MSSTR 2004-2 has a pool factor of 61% and is seasoned 12 months.

Further information regarding current delinquency, loss and credit enhancement statistics is available on the Fitch Ratings web site at 'www.fitchratings.com'.

Fitch's rating definitions and the terms of use of such ratings are available on the agency's public site, 'www.fitchratings.com'. Published ratings, criteria and methodologies are available from this site, at all times. Fitch's code of conduct, confidentiality, conflicts of interest, affiliate firewall, compliance and other relevant policies and procedures are also available from the 'Code of Conduct' section of this site.