The Commerce Department this morning estimated that U.S. retail sales declined by a seasonally adjusted 2.7% in December. Excluding auto sales which fell 0.7% - the retail sector experienced the largest slowdown on record during the latest month, with sales declining 3.1%.

Retail sales have backpedaled for 6 consecutive months now, marking the longest continuous decline on record. Compared to a year ago, sales in December are 9.8% lower. Excluding autos, sales have receded 6.7% from the same period a year earlier. For all of 2008, retail sales have fallen a seasonally adjusted 0.1% compared to 2007.

Most all of the retail sectors were hit hard during the latest month, save the health and personal care industry; sales at those stores increased 0.4%.