2008-05-07 23:35:11 -

- Fitch Ratings has affirmed the following UBS Mortgage Asset Securitization Transactions, Inc. (MASTR) mortgage pass-through certificates. Unless stated otherwise, any bonds that were previously placed on Rating Watch Negative are removed.

Series 2003-1, Pool 2

--Class 2-A at 'AAA';

--Class 30-B-1 at 'AAA';

--Class 30-B-2 at 'AAA';

--Class 30-B-4 at 'A+'.

The collateral

on the aforementioned transactions consists of 15- and 30-year fixed-rated mortgages extended to prime borrowers. As of the March 2008 remittance date, the deal has experienced 0.04% of loss (as a percentage of original balance). There are no loans more than 30 days delinquent and the pool factor is approximately 17%. Well Fargo Bank N.A. (rated 'RMS1' by Fitch) is the master servicer for the deal.

Class 2-A4 has a financial guaranty provided by MBIA. For more information please refer to 'Fitch Moves to Underlying Ratings for MBIA-Insured Bonds' dated April 4, 2008, available on the Fitch Ratings web site at www.fitchratings.com.

Further information regarding current delinquency, loss, and credit enhancement statistics is also available 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.

Fitch Ratings, New York
Tara Sweeney, +1-212-908-0347
Michele Patterson, +1-212-908-0779
Sandro Scenga, +1-212-908-0278 (Media Relations)