U.S. home prices fell 4.3% on a year-over-year basis in the fourth quarter as foreclosures and slowing sales buoyed inventory levels, Freddie Mac said Monday in its Conventional Mortgage Home Price Index. “Foreclosed-property and short sales remain a big part of the market. However, new foreclosures will begin to gradually slow,” said Frank Nothaft, Freddie Mac’s chief economist. “Delinquency rates reported by the Mortgage Bankers Association continue to recede from their peaks but remain high, particularly in distressed areas of the country.” Home prices fell in every U.S. geographical region in the fourth quarter, with the steepest declines occurring in the Mountain region, where home values fell more than 4%. The region includes the states of Arizona, Colorado, Idaho, Montana, New Mexico, Nevada, Utah and Wyoming. Home values in the mountain region also plummeted 9.6% in the past 12 months and 20% over a five-year period. Prices remained the most stable in the Mid-Atlantic region, where the states of New Jersey, New York and Pennsylvania experienced  a 1.1% drop in fourth-quarter home prices. Write to Kerri Panchuk.