Premier Mike Baird has admitted his office called an investment bank before it altered a report critical of the impact of electricity privatisation on the state budget, forcing him on the defensive over his main policy 10 days from the election.

UBS - one of two banks handling the electricity privatisation plan for the government - said in the initial report it would damage the budget in the long term due to the loss of billions of dollars in dividends and other payments.

NSW Premier Mike Baird says the original UBS report did not take into consideration the 'broad economic benefit' of electricity privatisation. Credit:Edwina Pickles

But the bank - which stands to benefit by earning millions of dollars in fees if the transaction proceeds after the March 28 election - reissued the report with an addendum removing a statement the transaction was "bad for the budget".

On Wednesday the Premier admitted staff in his office had contacted the bank shortly before it reissued the report.