Prime Minister John Key on Monday said the $6B figure related to proceeds of state-owned assets was to "our best estimates."

The PM's statement was a modification of how Finance Minister Bill English described the proceeds of state-owned assets sales.

Mr. English said during his presentation of the Budget policy statement last week that Treasury's estimate of $6 billion in sale proceeds from the minority sale of five state-owned assets "is not our best guess - it's just a guess," a comment which drew negative reaction, the New Zealand Herald reported.

The asset sale proceeds will determine the Government's capital spending programme, and borrowing for capital expenditure will be offset by whatever it gets for the assets up for sale -- four energy companies including Mighty River Power, and Air New Zealand.

Mr. Key also hinted Monday that any sale of Air New Zealand shares could be delayed until the aviation market picked up.

The initial estimates for the sales had been between $5 billion and $7 billion, and the advice Mr. Key had was that it would be about $6 billion.

"I'm confident of those numbers as best you can be but (Mr. English's) basic point is that there is a degree of subjectivity there because of the variables and moving parts, just as there is when we put together any set of budget predictions," the PM said.