Freightways is the latest listed company to warn tax changes will affect its bottom line.
In the 2010 Budget, the Government removed depreciation allowances on buildings and cut the company tax rate from 30% to 28%, both of which will take effect from 1 July next year.
Freightways says the changes will reduce its full year after-tax profit by $6 million this year.
And it warns more adjustments may be needed, depending on a review of which buildings are affected by the tax changes.
But the company says the adjustment is a one-off non-cash accounting entry, and has no impact on its underlying profitability, cashflows or dividend policy.
Shares in Freightways fell by 3 cents to $2.82 on Monday morning.