NEW YORK (AP) — Rates on fixed mortgages rose for the fourth straight week this week, hitting 4.61 percent. The surge could slow refinancings and further hamper the housing market.

The average rate on a 30-year fixed loan increased sharply from last week's rate and is well above the 4.17 percent rate hit a month ago — the lowest level on records dating back to 1971.

The average rate on a 15-year fixed loan rose to 3.96 percent. Rates hit 3.57 percent last month — the lowest level since 1991.

Rates are rising after plummeting for seven months. Investors are selling Treasury bond in anticipation of an extension of tax cuts and unemployment benefits that could boost the economy. That is raising the yield on Treasury bonds. Mortgage rates tend to track those yields.