The Government will release its Business Tax Review proposals for consultation by the middle of June next year, it says.
Finance Minister Michael Cullen said the scope of the promised review, which was part of post-election support deals with United Future and New Zealand First, was still being considered.
Buthe said it would not be a matter of just "tinkering with the tax rules".
"We envisage some very bold measures emerging."
Potential changes were aimed at giving better incentives for businesses to improve productivity and improving New Zealand's competitiveness with Australia.
"Lifting labour and capital productivity is critical to raising New Zealand's sustainable growth rate and to restoring New Zealand to the top half of the OECD (Organisation for Economic Co-operation and Development) in terms of per capita income. The review will be integral to this process," Dr Cullen said.
United Future leader and Revenue Minister Peter Dunne said it was important the process was wide-ranging and timely.
