The Associated Press

IRVINE, Calif. -- California is still dominating the foreclosure scene.

California cities made up seven of the top 10 metro areas with the highest rates of new foreclosures in the first six months of this year, according to data to be released Thursday by RealtyTrac, which tracks foreclosure properties. That's unchanged from the same time last year.

Foreclosure activity also spiked by more than 25 percent in and around Philadelphia, Chicago and New York. The new inventory could start hitting the market in the next several months, potentially weighing further on home values.

Stockton, Calif., located south of Sacramento, had a higher foreclosure rate than any other metro area in the U.S. in the first half of 2012. About 2.7 percent of homes -- or one of every 38 -- received a foreclosure filing between January and June. That rate was more than triple the national rate of 0.8 percent.

Stockton itself filed for Chapter 9 protection last month, making it the largest American city ever to declare bankruptcy. Officials were unable to reach a deal with the city's creditors to restructure hundreds of millions of dollars of debt.

Other Central Valley cities with high rates of new foreclosure filings were: Modesto, Merced, Bakersfield and Visalia-Porterville. Elsewhere in California, Riverside-San Bernardino-Ontario and Vallejo-Fairfield made the list. The Atlanta, Phoenix and Las Vegas metro areas rounded out the top 10.

It's a familiar template. Eight of the cities -- all except Atlanta and Visalia-Porterville -- were among the top 10 on RealtyTrac's list last year.

The number of U.S. homes entering the foreclosure process for the first time increased in May and June, as banks aim to make up for time lost last year when mortgage lenders grappled with allegations that they had processed foreclosures without verifying documents. The nation's biggest lenders reached a $25 billion settlement in February with state officials. That's cleared the way for banks to address their backlog of unpaid mortgages. California saw an 18 percent spike last month in foreclosure starts, or homes placed on the foreclosure path for the first time.

But Thursday's data also showed glimmers of encouraging news. Nine of the 10 cities with the highest rates saw rates drop year-over-year. Stockton's rate fell from 3.2 percent in the first half of 2011.

There are some 3 million U.S. homes behind on their mortgages, according to the Mortgage Bankers Association.