Following a big jump last week, the 30-year fixed-rate mortgage average fell 11 basis points to 6.52%, according to Freddie Mac’s survey of thrifts, commercial banks and mortgage lending companies for the week ended July 31. A year earlier, the 30-year averaged 6.68%.

The average 15-year fixed-rate was also down 11 BPS, to 6.07%, Freddie said.

“Mortgage rates moved lower this week as a drop in commodity prices eased market concerns over inflation pressures,” Freddie’s Chief Economist Frank Nothaft explained. “For instance, the Department of Energy reported that gasoline prices were the lowest since the end of May, and oil prices were at levels not seen since early May.”

A benchmark for fixed-mortgage rates, the 10-year Treasury yield, was 3.97% early today, according to CNNMoney. The 10-year yield fell from 4.05% seven days earlier.

Half of the panelists surveyed by Bankrate.com for the week July 31 to Aug. 6 expected rates to increase by at least 3 BPS during the next 35 to 45 days. Nearly one-third projected rates will fall, while 19% saw no change ahead.

The 5-year Treasury-indexed hybrid ARM averaged 6.07%, better than 6.16% the previous week, Freddie said.

The average 1-year Treasury-indexed ARM was 5.27%, tumbling 22 BPS from last week, according to Freddie’s survey. The yield on the 1-year Treasury itself was 2.33% yesterday, down from 2.40% a week prior, according to data published by the U.S. Treasury Department.

Another ARM index, the 6-month London Interbank Offered Rate or LIBOR, was 3.12% Wednesday, off from 3.14% the previous Wednesday, Bankrate.com reported.

Reflecting the prior week’s rising rates, the ARM share moved down to 7% from 9% one week earlier, according to the Mortgage Bankers Association’s Weekly Mortgage Applications Survey for the week ending July 25.

MBA said overall applications fell 14%, bringing the Market Composite Index to 420.8. While purchase applications declined 8%, applications for refinances tumbled 23% — pushing the refinance share to 35% from 39% the prior week.