Existing home sales declined 3.6 percent to a seasonally adjusted annual rate of 5.57 million units last month amid decreases in all four regions. Unseasonably cold weather probably accounted for some of the weakness as sales in the Northeast and Midwest fell sharply. November’s sales pace was revised down to 5.78 million units, still the highest level since February 2007. Economists polled by Reuters had forecast home sales falling 2.2 percent to a 5.70 million-unit rate in December from a previously reported 5.81 million-unit pace in November.