Subprime, Alt-A mortgage delinquencies rising-S&P

NEW YORK, May 22 (Reuters) - Delinquencies in U.S. subprime debt and higher-quality mortgages known as Alt-A securities are continuing to increase, Standard & Poor's said on Thursday.

Delinquencies for Alt-A mortgages rated between 2005 and 2007 are climbing, with total delinquencies rising as high as 17 percent in some cases, more than 6 percentage points higher than previous estimates, S&P said in a report. (Reporting by Walden Siew, Editing by Chizu Nomiyama)