By Ruth Mantell
WASHINGTON (MarketWatch) — U.S. home prices rose in December, and saw the largest year-over-year gain since 2006, according to the S&P/Case-Shiller home-price index released Tuesday. The S&P/Case-Shiller 20-city composite posted a nonseasonally adjusted 0.2% increase in December, following a 0.1% decline in November. After seasonal adjustment, home prices rose 0.9% in December. “Home prices ended 2012 with solid gains,” said David Blitzer, index committee chairman at S&P Dow Jones Indices. Looking at longer-term trends, December’s prices were up 6.8% from the same period in the prior year — the largest annual gain since July 2006 – with increases in 19 of 20 cities. New York was the only city with a year-over-year decrease, falling 0.5%. Low inventories and increasing demand have supported prices over the past year. Despite housing-market gains, prices remain about 29% below a bubble peak in 2006, according to Case-Shiller data.