NEW YORK (CNN/Money) - Rates for long- and short-term mortgages dipped again this week as investors listened to Federal Reserve Chairman Alan Greenspan's testimony to Congress implying no clear signs of a slowdown in the housing sector, economists said Thursday.

Freddie Mac reported that the 30-year mortgage averaged 6.49 percent in the week ending July 19, with an average of 0.6 point payable up front to the lender. The rate dropped from an average 6.54 percent last week and remained lower than its average 7.08 percent a year ago.

The 15-year fixed-rate mortgage averaged 5.93 percent, down from 6 percent last week and down from 6.65 percent a year ago. The 15-year averaged 0.5 point payable up front.

One-year adjustable-rate mortgages indexed to the Treasury averaged 4.50 percent, with an average 0.5 of a point due up front, down from 4.66 percent last week and down from an average of 5.62 percent a year ago.

"Long-term interest rates were little changed headed into Fed Chairman Greenspan's testimonies to Congress this week," Freddie Mac chief economist Frank Nothaft said. "On Monday the market priced in a 25 percent chance that the Fed would lower interest rates at the August FOMC meeting, owing to the continued decline in the stock market. This allowed interest rates for 1-year ARMs to decline a bit." (Read more about increasing the retail value of a home.)

Freddie Mac (FRE: down $1.82 to $56.77, Research, Estimates), or Federal Home Loan Mortgage Corp., is a publicly-traded company the government established in 1970 to provide a flow of funds to mortgage lenders. It buys mortgages from banks, bundles them and then resells them as mortgage-backed securities.

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Its products, and the products of other similar entities, have become increasingly popular as an alternative to government-backed bonds, particularly with international investors.