Oct. 1 (Bloomberg) -- New foreclosures tripled in Los Angeles and doubled in Seattle in the third quarter as the worst housing crisis since the Great Depression continued to deepen, the online real estate data company PropertyShark.com reported.

The number of new foreclosures in Los Angeles jumped to 15,749 from 5,322 in the same period a year earlier, New York- based PropertyShark said today in a report. New foreclosures in Seattle rose to 501 from 251, the second biggest gain in the study of four U.S. cities including New York and Miami.

U.S. mortgage foreclosures are at the heart of the global credit crisis that toppled Lehman Brothers Holdings Inc. last month and caused a record 777-point drop in the Dow Jones Industrial Average on Monday. Foreclosures rose to 2.75 percent of all U.S. mortgages in the second quarter, the highest ever, and a record 6.41 percent of borrowers were 30 days or more behind in their payments, the Mortgage Bankers Association said in a Sept. 5 report.

New York City foreclosures climbed 60 percent to 1,118, led by Staten Island and Queens. Property seizures in Manhattan were ``virtually nonexistent'' as most of the 35 auctions scheduled for the third quarter were called off after owners and lenders worked out deals, the report said.

Miami's Rate Jumps

Miami foreclosures rose 58 percent to 2,538.

PropertyShark counts properties scheduled for auction for the first time during the quarter as foreclosures and excludes homes that have been in and out of the foreclosure process or have been subject to auction delays. The data is collected from government records and legal notices.

House prices in 20 U.S. cities declined in July at the fastest pace on record, signaling the worst housing recession in a generation had yet to trough even before the credit crisis, according to a report issued yesterday.

The S&P/Case-Shiller home-price index dropped 16.3 percent from a year earlier, more than forecast, after a 15.9 percent decline in June, according to a Sept. 30 report.

Sales of previously owned homes fell 2.2 percent in August from the prior month and were 32 percent below their historic high reached in September 2005, the National Association of Realtors said in a report last week.

To contact the reporter on this story: Kathleen M. Howley in Boston at kmhowley@bloomberg.net.

Last Updated: October 1, 2008 15:11 EDT