The NAR said the index that tracks contracts of intention slipped 0.4 percent month-to-month to 110.9.
The index is a comparison to the monthly average for 2001, its first year, which was assigned a value of 100.
The NAR said it had revised its May reading for the index to a slightly lower 111.3 -- still leaving it as the highest reading since December 2006, when it stood at 112.8.
In June, the 26th consecutive month of improvements on an annual basis, the index was 10.9 percent higher than June 2012, when the index stood at 100.
The Pending Home Sales Index for the Northeast held steady in May at 87.2, but is 12.2 percent higher than June 2012.
In the Midwest, the index, dropped 1 percent to 114.3, but is 19.5 percent higher than June 2012.
From May, the index fell 2.1 percent in the South to 118.3, although that is a gain of 9.5 percent compared with the past 12 months. In the West, the index came to 114.2, up 3.3 percent from May and 4.4 percent from June 2012.