One of the Berejiklian government's biggest privatisation deals has been called into question after a critical report found NSW may have missed out on securing a higher price for it electricity assets.

In a blow to NSW's signature asset recycling strategy, a new Auditor-General's report said there were "shortcomings" in the process to lease the $16 billion electricity company, Ausgrid.

Former NSW premier Mike Baird and then Treasurer Gladys Berejiklian announce the lease of Ausgrid in 2016. Credit:Peter Rae

In October 2016, then premier Mike Baird announced that AustralianSuper and IFM investors would pay $16.189 billion for 50.4 per cent of Ausgrid on a 99-year lease after an unsolicited proposal to the government.

The proposal was revealed a month after Chinese bids for the original tender were blocked on national security grounds by the then federal Treasurer Scott Morrison.