WASHINGTON — Rising foreclosures are weighing on the U.S. housing market, reducing prices and keeping new-home sales weak.

Foreclosed homes are usually sold at steep discounts, thereby lowering average prices. And by expanding the supply of low-priced previously occupied homes, foreclosures tend to limit demand for new homes.

Some economists expect foreclosures to keep prices under pressure this year, even though they think sales of previously occupied homes will rise.

Banks are stepping up foreclosures in about half the states. The increase comes after state officials settled a dispute in February with five of the biggest mortgage lenders over foreclosure abuses.

“Foreclosures, excess supply and weak demand will drive home prices … down at least another 5 percent,” said Patrick Newport, an economist at IHS Global Insight.

The Standard & Poor’s/Case-Shiller home-price index, released Tuesday, showed that prices dropped in February from January in 16 of the 20 cities it tracks. That’s the sixth straight decline.

And new-home sales fell sharply in March, the Commerce Department said. Sales dropped 7.1 percent to a seasonally adjusted annual rate of 328,000.

Still, there were good signs in both reports. New home sales were revised sharply upward in February to show a 7.3 percent gain, much larger than initially reported. That suggests that warm winter weather might have pulled some sales into February that normally would have occurred in March.

As a result, new-home sales rose 7.5 percent in March compared with a year earlier.

And the pace of decline in the S&P/Case-Shiller index slowed. Some economists said that suggests prices are stabilizing. The index fell 3.5 percent over the 12 months that ended in February. That’s the smallest annual drop in a year.