WASHINGTON (AP) — Average U.S. rates on fixed mortgages rose this week in the wake of comments by Federal Reserve Chairman Janet Yellen suggesting that the Fed could start raising short-term interest rates by mid-2015.

Mortgage buyer Freddie Mac says the average rate for the 30-year loan increased to 4.40 percent from 4.32 percent last week. The average for the 15-year mortgage rose to 3.42 percent from 3.32 percent.

A key home-price index showed Tuesday a robust 13.2 percent increase in January compared with 12 months earlier. But the Standard & Poor's/Case-Shiller 20-city index was down from a 13.4 percent increase in 2013 and was the second straight decline.

There have been signs recently that the home-sales market could pick up in the coming months.