Existing home sales are seen rising 6.0 percent to 5.62 million units after growing by 6.8 percent in March, with forecasts between 5.42 million and 5.80 million.

* S&P/Case-Shiller 20-city index is seen declining 0.3 percent, seasonally adjusted, in March after a 0.1 percent dip, and increasing 2.4 percent year-over-year after a 0.6 percent rise. Estimates for the month range from a 0.5 percent drop to a 0.3 percent rise, and the annual rise forecasts span from 0.6 percent to 3.3 percent.

* New home sales are seen up to 420,000 units in April from 411,000 in March.

FACTORS TO WATCH:

These indicators will shed light on demand for houses in the weeks before and just following the end of a popular government incentive aimed at steadying a floundering market.

The April 30 deadline for homebuyer tax credits of up to $8,000 pulled many sales forward, likely draining activity from the usually heated spring and summer months.

Economists say it will take several more months before its clear whether the market can stand on its own or retreats anew after the credit's demise.

New and existing home sales likely were robust in April as buyers raced to beat the deadline for the credit. This would follow a five-month high in pending sales of previously owned homes in March.

If they could get it done, they got it done, inflating sales last month in a mad rush for the purchase incentive, said Jonathan Corr, chief strategy officer at Ellie Mae in Pleasanton, California.

Affordability has barely been better and that should put a floor under the housing market.

Prices have stabilized at depressed levels, down an average of about 30 percent from 2006 peaks. Mortgage rates are bumping up against record lows, thanks to the euro zone-driven flight to safety that slashed the Treasury yields use to peg home loan rates.

Amid the reports of hearty demand for houses in April and steadying prices, there will be evidence of the widely expected demand slump in the weeks after the tax credit expired.

On Wednesday, the Mortgage Bankers Association details the latest week's loan activity. Demand for mortgages to buy a house sank to a 13-year low in the second week without the tax credit, the industry group reported this week.

MARKET IMPACT:

U.S. financial markets are widely expecting April's home sales to extend the March uptrend as buyers were spurred on by the impending tax credit deadline. Home prices are seen rising this year and next, though they may dip first and it will take years to recover to pre-crash levels.

Unemployment near 10 percent and foreclosure sales will keep prices from rising much any time soon.

If debt market upheaval in Europe keeps the flight-to-quality alive in Treasuries, mortgage rates will stay low longer than many economists planned, supporting housing.

(Reporting by Lynn Adler; polling by Bangalore Polling Unit)

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