Adventure wear retailer Kathmandu has upgraded its profit forecast after better-than-expected sales in the first half of the financial year.

Kathmandu said sales growth was strong in the three months to September 30, while trade was "satisfactory" in the Christmas period.

It now expects net profit in the six months to December 31 to be between $NZ9.5 million and $NZ10.5 million ($A7.69 million and $A8.50 million), an increase of up to 75 per cent on its $NZ6 million net profit in the previous corresponding period.

"Our sales in Australia have continued to grow at a faster rate than New Zealand," chief executive Peter Halkett said in a statement on Friday.

The company expects up to 70 per cent of its full-year earnings to be made in the second half of the financial year and, therefore, remains cautious about its full-year performance.