Freddie Mac (FRE) said Friday its index that tracks U.S. home prices dropped at a 17.9% annual rate in the fourth quarter as every region of the U.S. saw flat or declining home values for the second straight period.

For the year, home prices dropped an average 9.5%, according to the mortgage giant's Conventional Mortgage Home Price Index, the largest annual decrease in the 39-year history of the index. The annual rate of decline in the third quarter was revised to 8%.

In addition, the mortgage giant said the fourth quarter marked the first time year-over-year declines were recorded in all nine regions of the country. The Pacific region led decliners with a 23% drop from a year earlier, while the fall for the West South Central area was a scant 0.1%.

"The deepening recession and the large inventory of for-sale homes continued to push home values down," Freddie Chief Economist Frank Nothaft said. "While historically low interest rates on long-term fixed-rate mortgages help the housing market, demand for homes was weakened by rising unemployment, wealth declines from declining stock market valuations, and general lack of consumer confidence.

Freddie's home-price index showed home prices fell 8.1% in the fourth quarter in the Pacific region from the third quarter. That was followed by the South Atlantic with a 6.5% drop and the East North Central with a 4.9% fall. The smallest drop was the West South Central division at 1.6%.

Earlier this week, S&P/Case-Shiller home-price indexes showed home prices continued their multiyear slide, with prices now similar to late-2003 levels.

-By Lauren Pollock, Dow Jones Newswires; 201-938-5964; lauren.pollock@dowjones.com