Australia’s biggest electricity company AGL has rejected three of the four experts nominated for the board by billionaire shareholder Mike Cannon-Brookes.

Seeking a change of strategy and culture, his Grok Ventures investment firm put forward four independents for election to the board: former energy regulator Kerry Schott, sustainability expert Christine Holman, Tesla’s Mark Twidell and experienced board chair John Pollaers.

In a letter to shareholders on Friday, AGL endorsed Mr Twidell but not the others.

AGL chair Patricia McKenzie said it was “unusual” for a non-controlling shareholder (11.28 per cent) to nominate four candidates.

“The board is of the view that appointing all four of the Grok candidates would not add to the overall effectiveness of the board,” she said.

Grok Ventures welcomed the endorsement of Mr Twidell but warned the transformation task ahead of AGL as Australia’s biggest carbon emitter cannot be underestimated.

‘Makes no sense’

“It makes no sense to us – or a growing list of shareholders – that the board is rejecting highly-qualified, independent directors who are committed to helping them make AGL the leading green gentailer in the world,” a Grok spokesman said.

“We disagree that the incumbent directors have the breadth of skills required to execute on this transition,” he said.

“They quite simply need more help, particularly with execution which has been underwhelming to this point.”

This year Mr Cannon-Brookes scuppered the energy giant’s planned demerger, which would have created a power retailer and hived off ageing coal-fired operations that would have operated for longer.

Readying for another showdown at the annual general meeting next month, Grok said it would continue to push the nominations of Dr Pollaers, Dr Schott and Ms Holman.

“To be clear, as AGL’s largest shareholder, Grok is committed to working with the Board to help effect the necessary changes and make the most of the decarbonisation opportunity,” the spokesman said.

“Part of this commitment was to help find independent director candidates with the skills the company requires for this transition.”

Grok said it would be campaign directly with AGL’s 150,000 shareholders in the lead up to the meeting scheduled for November 15.

Shareholders will also vote on AGL’s climate transition plan.

-AAP