Two separate indices calculated by Standard & Poor's showed house prices in major US metropolitan areas continued to fall in April, although year-on-year declines show signs of slowing. Both the 10-city and 20-city composite indices have returned to their mid-2003 levels, according to the S&P/Case-Shiller Home Price Index, released today. The 10-city index slid 18% while the 20-city index slid 18.1% in April, compared with the year-ago period. The rate of decline slowed from the annual pace of -18.7% seen in both composites last month. Month-on-month performance fared a bit better, however, as every metro area except for Charlotte experienced improvement in monthly returns over March. “While one month’s data cannot determine if a turnaround has begun; it seems that some stabilization may be appearing in some of the regions,” said David Blitzer, chairman of the committee in charge of S&P's index. "We are entering the seasonally strong period in the housing market, so it will take some time to determine if a recovery is really here." Phoenix posted the largest annual decline of 35.3%, while Las Vegas slipped 32.2% from last year and San Francisco fell 28%. Denver, Dallas and Boston posted the best performance in terms of annual declines, down 4.9%, 5% and 7.7%, respectively. On a month-on-month basis, Dallas saw 1.7% gain from March while Las Vegas lost 3.5%. The S&P/Case-Shiller HPI tracks the value of US single-family housing units as recorded by financial market solution provider Fiserv. The indices bear a base value of 100 in January 2000, meaning an index of 150 indicates a 50% appreciation rate since January of 2000 for an average home within the metro market. The 10-City Composite measured 150 in April, while the 20-City Composite came in at 139 for the month. Write to Diana Golobay.