Existing-home sales eased in March from inventory constraints, which continued to pressure home prices, according to the National Association of Realtors (NAR). Total existing-home sales, which are completed transactions that include single-family homes, townhomes, condominiums and co-ops, declined 0.6 percent to a seasonally adjusted annual rate of 4.92 million in March from a downwardly revised 4.95 million in February, but remain 10.3 percent higher than the 4.46 million-unit pace in March 2012.

Sales have been above year-ago levels for 21 consecutive months, while prices show 13 consecutive months of year-over-year price increases.

Lawrence Yun, NAR chief economist, said there is more demand than supply in the current market. "Buyer traffic is 25 percent above a year ago when we were already seeing notable gains in shopping activity," he said. "In the same timeframe housing inventories have trended much lower, which is continuing to pressure home prices. The good news is home construction is rising and low mortgage rates are continuing to keep affordability conditions at historically favorable levels. The bad news is that underwriting standards remain excessively tight, while renters are getting squeezed by higher rents."

Total housing inventory at the end of March increased 1.6 percent to 1.93 million existing homes available for sale, which represents a 4.7-month supply at the current sales pace, up from 4.6 months in February. Listed inventory remains 16.8 percent below a year ago when there was a 6.2-month supply.

"The inventory improvement last month results from a seasonal gain, but conditions continue to broadly favor sellers. We need a housing supply of over 6 months to have a generally balanced market between home buyers and sellers, but it's unlikely we'll get there without greater increases in housing construction," Yun said.

The national median existing-home price for all housing types was $184,300 in March, which is 11.8 percent higher than March 2012. The March increase is the strongest since November 2005 when it rose 12.9 percent from a year earlier, and the last time there were 13 consecutive months of year-over-year price increases was from May 2005 to May 2006.

Distressed homes — foreclosures and short sales — accounted for 21 percent of March sales, down from 25 percent in February and 29 percent in March 2012. Thirteen percent of March sales were foreclosures and 8 percent were short sales. Foreclosures sold for an average discount of 15 percent below market value in March, while short sales were discounted 13 percent.

According to Freddie Mac, the national average commitment rate for a 30-year, conventional, fixed-rate mortgage increased to 3.57 percent in March from 3.53 percent in February; it was 3.95 percent in March 2012.

NAR President Gary Thomas, broker-owner of Evergreen Realty in Villa Park, Calif., said homes are selling much faster. "The typical home sold in March was on the market for one month less than it took to sell a year ago," he said. "Multiple bidding is becoming more common, and more homes are selling above the asking price, so buyers need to move quickly and follow their Realtor's advice for contingencies when making contract offers."

The median time on market for all homes was 62 days in March, down from 74 days in February and is 32 percent below 91 days in March 2012. Short sales were on the market for a median of 81 days, while foreclosures typically sold in 46 days and non-distressed homes took 66 days. Thirty-seven percent of all homes sold in March were on the market for less than a month.

First-time buyers accounted for 30 percent of purchases in March, unchanged from February; they were 33 percent in March 2012.

All-cash sales were at 30 percent of transactions in March, down from 32 percent in February; they were 32 percent in March 2012. Individual investors, who account for most cash sales, purchased 19 percent of homes in March, down from 22 percent in February; they were 21 percent in March 2012.

Single-family home sales slipped 0.2 percent to a seasonally adjusted annual rate of 4.32 million in March from 4.33 million in February, but are 9.1 percent above the 3.96 million-unit level in March 2012. The median existing single-family home price was $185,100 in March, up 12.1 percent from a year ago.

Existing condominium and co-op sales fell 3.2 percent to an annualized rate of 600,000 units in March from 620,000 in February, but are 20 percent higher than the 500,000-unit pace a year ago. The median existing condo price was $178,900 in March, which is 10.4 percent above March 2012.

Regionally, existing-home sales in the Northeast were unchanged at an annual rate of 630,000 in March and are 6.8 percent above March 2012. The median price in the Northeast was $237,000, up 3.0 percent from a year ago.

Existing-home sales in the Midwest rose 1.8 percent in March to a pace of 1.16 million and are 14.9 percent above a year ago. The median price in the Midwest was $141,800, up 7.8 percent from March 2012.

In the South, existing-home sales slipped 1.5 percent to an annual level of 1.95 million in March but are 12.7 percent above March 2012. The median price in the South was $161,700, which is 10.4 percent above a year ago.

Existing-home sales in the West declined 1.7 percent to a pace of 1.18 million in March but are 4.4 percent above a year ago. With notably constrained inventory conditions, the median price in the West rose to $258,100, up 26.1 percent from March 2012.