Applications for U.S. home mortgages jumped for a third consecutive week as plunging interest rates encouraged more homeowners to seek refinancings, an industry group said on Wednesday.

The Mortgage Bankers Association said its seasonally adjusted index of refinancing applications surged 16.9 percent in the week ending Jan. 18 to 4,178.2, the highest level since March 2004. The activity was up 92 percent since the beginning of November and more than offset a 4.6 percent fall last week in the index for home purchase applications to 439.9, it said.