NEW YORK (CNNMoney.com) -- U.S. mortgage applications fell last week on a drop in refinancing activity as interest rates ticked higher, an industry trade group said Wednesday.

The Mortgage Bankers Association said its seasonally adjusted index of requests for home loans for the week ended Oct. 13 eased 2.2 percent to 585.8 from the previous week's 599.1.

Borrowing costs on 30-year fixed-rate mortgages, excluding fees, increased to 6.33 percent from 6.27 from the previous week.

The MBA's seasonally adjusted purchase mortgage index increased by 0.4 percent to 384.7 from 383.3 one week earlier.

The group's seasonally adjusted index of refinancing applications decreased by 5.3 percent to 1758.2 from 1857 the previous week.

Fixed 15-year mortgage rates averaged 6.01 percent, up from 5.9 the previous week. Rates on one-year adjustable-rate mortgages (ARMs) increased to 5.94 percent from 5.88 percent.

The ARM share of activity decreased to 26.5 percent of total applications, from 26.9 the previous week.

The MBA's survey covers about 50 percent of all U.S. retail residential mortgage loans. Respondents include mortgage bankers, commercial banks and thrifts.

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