Home buyers paid higher interest rates on conventional home mortgage loans in July than in June, the Federal Housing Finance Agency reported Thursday.

The average interest rate on conventional 30-year fixed-rate mortgages increased 19 basis points to 5.31%, while average rates for 15-year fixed-rate loans rose nine basis points, to 4.89%, according to the FHFA. Conventional mortgages cover loans up to $417,000. The FHFA said the average loan-to-price ratio for July rose to 74.9%, from 74.4% in June, while the average loan amount fell by $5,700, to $227,300.

Results for July reflect loans that closed between July 27 and July 31; since interest rates typically are set 30 to 45 days before closing, the reported rates reflect market conditions prevailing in mid- to late June.

The FHFA, which oversees federal mortgage-finance firms Fannie Mae (FNM) and Freddie Mac (FRE), said the report didn't include any data on adjustable-rate mortgages due to an insufficient sample size.

A composite rate of all mortgage loans, including adjustable-rate loans, was 5.25% in July, up 17 basis points from the 5.08% rate in June. The national average contract mortgage rate for the purchase of previously occupied homes by combined lenders, used as an index in some adjustable-rate mortgage contracts, was 5.26% for loans closed in July, fractionally higher than in June.

The FHFA also reported that the effective interest rate, which reflects the amortization of initial fees and charges, was 5.35% in July, up 19 basis points from the 5.16% level for June. Initial fees and charges were 0.67% of the loan balance in July, up nine basis points from June.

For conventional mortgage loans originated in July, 42% were "no-point" mortgages, compared with a 45% rate in June. The FHFA said the average term for loans in July was 28.4 years, compared with 28.5 years in June.

-By Judith Burns, Dow Jones Newswires; 202-862-6692; Judith.Burns@dowjones.com