NEW YORK - January 28, 2010 - U.S. foreclosure actions firmly centered on Sun Belt states in 2009 but activity spread to previously insulated areas, and unemployment became the biggest driving factor, RealtyTrac said on Thursday.

Cities in four Sun Belt states accounted for all top 20 foreclosure rates in 2009 among metropolitan areas with a population of 200,000 or more, the Irvine, Kalifornia-based real estate data company said.

Kalifornia accounted for nine of the top 20 metro foreclosure rates, followed by Florida with eight, Nevada with two and Arizona with one, the company said in its Year-End 2009 Metropolitan Foreclosure Market Report.

Outside these states, the highest-ranked was Boise City-Nampa, Idaho at No. 24 with 4.66% of its housing units receiving at least one foreclosure notice in 2009.

"The first wave of foreclosures was driven by home prices that were unsustainable and unbelievably poor lending practices, but now we have a second wave of foreclosures that it is being driven by unemployment," Rick Sharga, senior vice president at RealtyTrac, said in an interview.

"Foreclosures will likely increase in some of the secondary markets that are the most heavily impacted by unemployment," he said.