The number of U.S. households that signed contracts to buy homes dipped in April following three consecutive monthly gains, a leading U.S. industry group reported on Wednesday.

The National Association of Realtors (NAR) said its index of pending home sales, which measures the number of contracts to buy previously-owned homes that have been signed but not yet closed, fell 5.5 percent to 95.5 in April from a downwardly-revised 101.1 in March, but was still 14.4 percent higher than the level a year ago.

NAR chief economist Lawrence Yun said a one-month setback in light of many months of gains does not change the fundamentally improving housing market conditions.

The NAR index is a leading indicator of future existing home sales, since there is usually one or two months' lag between signing a contract and closing a deal.

A reading of 100 indicates an average level of sales activity in 2001, when the index started. The reading was above the 100 threshold from March 2003 to April 2007, and then sank as the country fell into a deep recession caused by the housing debacle.

"Home contract activity has been above year-ago levels now for 12 consecutive months. The housing recovery momentum continues," Yun said.