WASHINGTON (MarketWatch) -- U.S. home prices rose 0.5% in the first quarter of the year compared with the fourth quarter, the slowest price gain in 10 years, the Office of Federal Housing Enterprise Oversight reported Thursday. The OFHEO price index is up 4.3% compared with the first quarter of 2006. Prices fell in seven states from the fourth quarter to the first, including Florida and California. Prices fell year-over-year in Massachusetts and Michigan. The biggest year-over-year price gains were recorded in the West, with Utah, Idaho, Montana, Wyoming and Washington at the top. Forty-six of the 285 cities recorded falling prices over the past year.