Fitch Downgrades 2 & Places 2 Classes on Rating Watch Negative from 3 MABS Securitizations.

NEW YORK -- Fitch has taken rating actions on the following Mortgage Asset Securitization Transactions (MASTR) Asset Back Securities Trust (MABS) mortgage pass-through certificates:

Series 2002-OPT1

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

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

--Class M-4 affirmed at 'A+';

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

--Class M-6 downgraded to 'BB-' from 'BBB-'.

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 downgraded to 'BB+' from 'BBB-'.

Series 2005-NC2

--Classes A-1 through A-4 affirmed at 'AAA';

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

--Class M-2 affirmed at 'AA+';

--Class M-3 affirmed at 'AA+';

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

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

--Class M-6 affirmed at 'A+';

--Class M-7 affirmed at 'A-';

--Class M-8 affirmed at 'BBB+';

--Class M-9 affirmed at 'BBB';

--Class M-10 is rated 'BBB' and placed on Rating Watch Negative;

--Class M-11 is rated 'BBB-' and placed on Rating Watch Negative.

The affirmations, affecting approximately $735 million of the outstanding certificates, are taken as a result of a stable relationship between credit enhancement (CE) and expected loss. The downgrades, affecting approximately $6.9 million of the outstanding certificates, are taken as a result of deterioration in the relationship between CE and expected loss. The Rating Watch Negative affects approximately $13.1 million of the outstanding certificates.

The collateral of series 2002-OPT1 and series 2003-WMC2 primarily consists of fixed-rate and adjustable-rate subprime mortgage loans secured by first and second liens on one- to four-family residential properties. The collateral of series 2005-NC2 primarily consists of adjustable-rate, interest-only, subprime mortgage loans secured by first liens on one- to four-family residential properties. The loans underlying series 2002-OPT1 were originated or acquired by Option One Mortgage Corp. and are serviced by Option One Mortgage Corp. (rated 'RPS1' by Fitch). The loans underlying 2003-WMC2 were originated or acquired by WMC, a mortgage banking company incorporated in the State of California and are services by Chase Home Finance, LLC (rated 'RPS1' by Fitch). The loans underlying series 2005-NC2 were originated or acquired by New Century Mortgage Corp. and are serviced by Ocwen Financial Corp. (rated 'RPS2' by Fitch).

Series 2005-NC2, classes M-10 and M-11 are placed on Rating Watch Negative because of current trends in the relationship between serious delinquency (DQ) and credit enhancement. This transaction has 6.8% of the current collateral balance in foreclosure (FC) and REO. In addition, the 60+ DQ (including loans in bankruptcy, FC, and REO) is 12.0% of the current collateral balance, which is relatively high compared to the subprime industry average. The OC is currently at target and providing 2.5% in credit enhancement to class M-12, which is not rated by Fitch. In addition, the annualized excess spread currently available to absorb losses is 0.51%.

As of the March 2007 distribution date, series 2002-OPT1 has a pool factor (i.e., current mortgage loans outstanding as a percentage of the initial pool) of 8% and is seasoned 52 months. Series 2003-WMC2 has a pool factor of 8% and is seasoned 42 months. Series 2005-NC2 has a pool factor of 72% and is seasoned 16 months. Further information regarding current delinquency, loss and CE 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.