Pending sales of existing U.S. homes fell in April to their lowest marks in four years, according a National Association of Realtors index released today.

The index based on signed purchase agreements in April fell to 101.4, a drop of 3.2% for the month. The index was down 4.5% in March and currently stands 10.2% lower than April last year.

The index is considered a leading indicator since it tracks contract signings. The association also tracks closings. The group reported last week that existing home sales dropped 2.6% in April, the lowest level in four years.