NEW YORK (Reuters) - U.S. single-family home prices rose by a seasonally adjusted 0.3 percent in July from June but were 4.2 percent lower than a year earlier and 10.5 percent below their April 2007 peak, the Federal Housing Finance Agency said on Tuesday.

The regulator's monthly home price index (HPI) for June was revised down to a 0.1 percent rise from a previously reported 0.5 percent increase.

The index rose to 200.1 in July from 199.4 in June, but was down from 208.9 a year earlier.

For the nine census divisions, seasonally-adjusted monthly price changes from June to July ranged from a 0.9 percent decline in the East South Central division to a 1.6 percent gain in the Pacific division.

The index is calculated using purchase prices of houses financed with mortgages that have been sold to or guaranteed by mortgage finance sources Fannie Mae (NYSE:FNM - News) or Freddie Mac (NYSE:FRE - News).