Single-family home prices in the Boston area increased slightly in March when seasonal adjustments are taken into account, a closely watched survey said today, suggesting the battered housing market may be stabilizing.

In the Boston area, prices were up 0.7 percent in March from February according to the S&P/Case-Shiller composite index.

The S&P/Case-Shiller composite index of 20 metropolitan areas nationwide recorded a 1.1 percent increase compared with the year before.

"While there has been improvement in some regions, housing prices have not turned," says David M. Blitzer, chairman of the Index Committee at S&P Indices. "This month’s report saw all three composites and five cities hit new lows. However, with last month’s report nine cities hit new lows. Further, about half as many cities, seven, experienced falling prices this month compared to 16 last time.

"After close to six consecutive months of price declines across most cities, this is relatively good news. We just need to see it happen in more of the cities and for many months in a row. Since we are entering a seasonal buying period, it becomes very important to look at both monthly and annual rates of change in home prices in order to understand the broader trend going forward."

Fifteen of the 20 cities in the composite index showed seasonally adjusted  increases in March, with Portland’s prices flat and only Atlanta, Chicago, Detroit and New York continuing to decline. Phoenix had the largest gains, with prices there increasing 2.7 percent. Overall, however, Q1 2012 still set a new record for lowest prices nationwide.