Horizon Energy Distribution has appointed Simmons Corporate Finance to appraise a $50 million partial takeover offer by Marlborough Lines.
The South Island distribution company wants 51% of Horizon, offering $3.96 per share, and valuing Horizon at $99 million.
Eastern Bay Energy Trust owns 77% of Horizon Energy and will be crucial to whether any bid succeeds.
Horizon says shareholders will receive a recommendation from the board on 13 October.
Marlborough Lines owns 51% of the network joint venture OtagoNet and has a 50% stake in Nelson Electricity.