Industry super fund HESTA, Merlon Capital Partners and BetaShares have joined the growing list of AGL Energy investors that have decided to back at least some of the board candidates proposed by its biggest shareholder Mike Cannon-Brookes, heightening the prospects of an enlarged but divided board at the embattled power supplier.

HESTA has voted for the election of two of the Grok picks, Mark Twidell and Christine Holman, while Merlon said it supported those two and former Energy Security Board chairman Kerry Schott. BetaShares supports all four.