Single-family home prices fell more than expected in October, data showed Tuesday, raising doubts that recent signs of improvement in the housing market would be sustained.

The S&P/Case Shiller composite index of 20 metropolitan areas dropped 1.2 percent on an unadjusted basis, worse than economists' expectations for a 0.5 percent fall. Prices dropped 0.6 percent in September.

For the year, home prices were down 3.4 percent in October.

Recent data have shown an improvement in home sales volumes and rising confidence among builders who have been breaking ground on new projects.

That had raised cautious optimism the housing market, one of the constraints on the economy, was on the brink of recovery.

In light of the more positive housing numbers we've seen in the last week or so, this might be a bit of a disappointment, said Omer Esiner, chief market strategist at Commonwealth Foreign Exchange in Washington.

The data on Tuesday showed prices declined in October in 19 of the 20 cities.

(Reporting By Lucia Mutikani; Editing by Padraic Cassidy)

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