Applications for U.S. home mortgages sagged for a third week in a row last week, even as mortgage rates eased slightly, an industry group survey showed on Wednesday.

The Mortgage Bankers Association said its seasonally adjusted index of mortgage application activity, which includes both refinancing and home purchase demand, fell 3.8 percent in the week ended Feb. 22.

The MBA's seasonally adjusted index of refinancing applications slipped 3.3 percent, while the gauge of loan requests for home purchases, a leading indicator of home sales, dropped 5.2 percent.

The refinance share of total mortgage activity was unchanged at 77 percent of applications, holding at the lowest level since July 2012.

Fixed 30-year mortgage rates averaged 3.77 percent, down 1 basis point from 3.78 percent the week before.

The survey covers over 75 percent of U.S. retail residential mortgage applications, according to MBA.