April, normally a robust month for sales of existing single-family homes, condo and coops, was not this year, according to data released Thursday by the National Association of Realtors.

Sales of existing homes dipped 0.8% to a seasonally adjusted annual rate of 5.05 million in April from a downwardly revised 5.09 million in March, 12.9% below April 2010, when sales were fueled by a federal home-buyer tax credit. The original March estimate was a rate of 5.10 million.Wall Street was expecting a rate of 5.20 million.

Prices fell, with the national median for all housing types dropping to $163,700 in April, 5% below April 2010. Distressed homes, which, according to the Realtors sell for an average discount from market of 20%, accounted for 37% of sales, down from 40% in March but up from 33% in April 2010.

Inventory rose by 9.9% to 3.87 million homes for sale, a 9.2-month supply compared to 8.3 months in March.

All-cash transactions accounted for 31% of sales in April, down from a record 35% in March. First-time buyers made up 36% of the market, up from 33% in March but down from 49% in April 2010 when the tax credit was in place. Investors slipped to 20% from 22% in March but up from 15% in April 2010.

Single-family sales fell 0.5% to a seasonally adjusted annual rate of 4.42 million from 4.44 million in March, 12.6% below the 5.06 million pace in April 2010. The median existing single-family home price dropped 5.4% from last April to $163,200.

Sales of condominiums and coops fell 3.1% to a pace of 630,000, 15% below the 741,000-unit level one year ago. The median price was down 2.3% to $167,300.

The Northeast led the declines with a drop of 7.5 percent to an annual pace of 740,000, down 32.1% from April 2010, with the median price down 7.3% to $225,400. Sales fell more modestly in the South and West, with declines of 1% to a pace of 1.95 million and 1.6% to a rate of 1.24 million, respectively. Year-over-year, the South was down 9.3% and the West down 0.8%, with prices off 4.1% to $142,800 in the South and down a 6.1% to $203,400 in the West.

Sales in the Midwest rose 5.7% from March to an annual rate of 1.12 million, 16.4% below a cyclical peak in April 2010. The median price in the Midwest was $133,200, down 5.1% from a year earlier.

The Realtors blamed the lackluster sales on a combination of tight credit and low appraisals.

"Although sales are clearly up from the cyclical lows of last summer, home sales are being held back 15 to 20% due to the very restrictive loan underwriting standards," said Lawrence Yun, chief economist for NAR."Although existing-home sales are expected to trend up unevenly through next year, unnecessarily tight credit is continuing to restrain the market, along with a steady level of low appraisals that result in contract cancellations."

NAR said a survey of its members showed 11% reported a contract was cancelled in April from an appraisal coming in below the negotiated price, 10% had a contract delayed, and 14% said a contract was renegotiated to a lower sales price as a result of a low appraisal.

Separately, the Mortgage Bankers Association reported Thursday that the delinquency rate for mortgage loans on one-to-four-unit residential properties increased to a seasonally adjusted rate of 8.32% of all loans outstanding as of the end of the first quarter of 2011, an increase of seven basis points from the fourth quarter of 2010 and a decrease of 174 basis points from one year ago, according to its National Delinquency Survey. The non-seasonally adjusted delinquency rate decreased 117 basis points to 7.79% this quarter from 8.96% last quarter. It also said the combined percentage of loans in foreclosure or at least one payment past due was 12.31% on a non-seasonally adjusted basis, a 129 basis point decline from 13.60% last quarter.

"Of particular importance is that the drop in the percentage of loans 90 days or more past due was driven by improving numbers for loans originated between 2005 and 2007," said Jay Brinkmann, MBA's chief economist. "These are the loans that drove the mortgage market collapse and now represent about 31% of loans outstanding but 65% of the loans seriously delinquent. Given that loans originated during this period are now past the point where loans normally default, and that loans originated since then generally have better credit quality, mortgage performance should continue to improve."