Wesfarmers Ltd says its pre-tax earnings will be cut by up to $20 million a month, as the company feels the impact of gas outages following an explosion that closed down the Varanus Island gas plant.

Wesfarmers Ltd says its pre-tax earnings will be cut by up to $20 million a month, as the company feels the impact of gas outages following an explosion that closed down the Varanus Island gas plant.