In its application to the regulator, made public this month, Z said its planned $785 million purchase of rival Chevron New Zealand's Caltex-branded network won't drive up prices at the pump because the target doesn't have retail price-setting power and the market will remain highly competitive.
A Caltex fact sheet says it has 147 outlets in New Zealand, supplies fuel to the aviation and shipping industries and is a partner in the AA Fuelcard loyalty scheme.
Z Energy is a shareholder in the rival FlyBuys scheme and its website says it has more than 200 outlets.
Z shares were unchanged at $5.89, and have climbed 27 per cent this year.