Mortgage rates fell for a fourth week, reducing borrowing costs for homebuyers during the key spring selling season.

The average rate for a 30-year fixed mortgage was 4.14% this week, down from 4.2% and the lowest since late October, Freddie Mac said in a statement today. The average 15-year rate slipped to 3.25% from 3.29%, the McLean, Va.-based mortgage-finance company said.

Sales of previously owned homes rose 1.3% in April, the first increase in four months, the National Association of Realtors said today. The drop in loan costs this month may help spur some would-be buyers, said Keith Gumbinger, vice president of, a Riverdale, N.J.-based mortgage-data firm.

"With a combination of a flatter trajectory for home prices and lower rates, that should be preserving affordability as we go through the spring homebuying season," Gumbinger said in a telephone interview yesterday.

Price gains have slowed, according to the S&P/Case-Shiller index of 20 U.S. cities. In the year ended February, the measure rose 12.9%, the smallest increase since August, after a 13.2% advance in the 12 months through January.

Bloomberg News