A regulator says mortgage rates fell in February, making buying a house more affordable.

The Federal Housing Finance Agency on Thursday said the average interest rate on conventional 30-year, fixed-rate, mortgage loans of $417,000 or less decreased 6 basis points to 5.03% in February.

The average interest rate on 15-year, fixed-rate loans of $417,000 or less decreased 19 basis points to 4.92% in February.

The FHFA regulates Fannie Mae (FNM), Freddie Mac (FRE) and the 12 Federal Home Loan banks.

The rates reported Thursday by the agency were calculated from a survey of purchase-money mortgages. The survey results reflect loans closed during the Feb. 23-28 period. Typically, the interest rate is determined 30 to 45 days before the loan is closed. So, the reported rates depict market conditions prevailing in mid- to late January, the agency said.

 
   -By Jeff Bater, Dow Jones Newswires; 202 862 9249; jeff.bater@dowjones.com