NEW YORK (CNNMoney.com) -- Mortgage rates fell for the seventh time in eight weeks after a small gain last week, said a survey released Thursday.

The 30-year fixed-rate mortgage (FRM) averaged 6.43 percent for the week ending Sept. 14, down from 6.47 percent, according to Freddie Mac's (Charts) Primary Mortgage Market Survey. A year ago, the 30-year FRM averaged 5.74 percent.

The 15-year FRM averaged 6.11 percent this week, down from 6.16 percent last week. A year ago, it averaged 5.32 percent.

Five-year adjustable-rate mortgages (ARMs) came in at 6.10 percent this week, down from 6.14 percent last week. A year ago, they averaged 4.46 percent.

One-year ARMs averaged 5.60 percent, down from 5.63 percent last week. A year ago, the one-year ARM averaged 4.46 percent.

"Although 30-year mortgage rates are about three-fourths of a percentage point higher than they were last year, it's good to keep in mind that rates have dropped from the high of 6.80 percent reached just eight weeks ago," said Frank Nothaft, Freddie Mac vice president and chief economist, in a statement.

"And with short-term interest rate increases seemingly on hold, for a while at least, interest rates overall should not experience any big shifts in either direction."

"The risk to our forecast of relatively stable mortgage rates is that inflation will unexpectedly heat up, causing bond markets to raise their expectations that the Fed will intervene by raising short-term rates. In that case, mortgage rates will again start to rise," he added.

Freddie Mac competes on the secondary market with Citigroup Inc. (Charts), Countrywide Financial Corp. (Charts) and Fannie Mae (Charts).

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