Freddie Mac said in a statement Thursday that the average interest rate on a 30-year fixed-rate mortgage was 6.46 percent, down from 6.49 percent last week. Borrowing costs fell sharply after topping 7 percent earlier this year, boosting home buyers' purchasing power and prompting some would-be buyers to give up the wait-and-see. The National Association of Realtors (NAR) reported Thursday that U.S. pre-owned home sales rose in July for the first time in five months. While sales of pre-owned homes rose 1.3 percent month-on-month in July, it was still the slowest July pace since 2010, indicating that high prices and a shortage of affordable listings are still keeping many Americans off. Buyers and sellers may also wait until financing costs fall further before making a decision. Sam Khater, chief economist at Freddie Mac, said: "The sharp drop in interest rates earlier this month and now hovering at just under 6.5 per cent is not enough to motivate potential buyers and we expect rates may need to fall by another percentage point to boost buyer demand."