About 75% of America's large metropolitan areas saw a year-on-year increase in home foreclosure activity in the first half of 2010, according to a new report.

RealtyTrac, an online marketplace for foreclosure properties, said 154 out of 206 metropolitan areas with a population of 200,000 or more saw an increase in foreclosure activity.

"While we're seeing early signs that foreclosure activity may have peaked in some of the hardest-hit markets, foreclosures continued to rise in three-quarters of the nation's metropolitan areas in the first half of the year," said James J. Saccacio, CEO of RealtyTrac.

Of the top-20 metro areas for foreclosure rate, nine were located in Florida and eight were in California.

Las Vegas had the highest foreclosure rate, with 6.6% of its housing units receiving a foreclosure filing. That's more than five times the national average.