The company said the plunging margins were the result of higher electricity costs, the one-off impact of an outage of its cracking unit and a $25 million loss from the losses incurred from the storage and export of intermediate products.

Those losses were partially offset by gains in trading and shipping.

The Lytton refiner margins for the second quarter of 2023 was $US5.66 a barrel compared with a 2022 price for the first half of $US22.25 and it ended the half year with a $SUS10.29 margin.

Ampol said this was because of weaker Singapore product cracks experienced in April and May and a higher proportion of lower-value finished products and intermediates produced during the outage to repair its own cracking unit.

Ampol’s unaudited earnings before interest and tax for the 2023 first half were about $575 million.

Its total fuel sales by volume were up 24 per cent for the first half of 2023 financial year with Australian fuel sales growing by 13 per cent. International sales were up 8 per cent. it also had a full six months contribution from Z Energy.

Ampol said its convenience retail division grew through strong shop performance and improved fuel margins.

Fuels and infrastructure (ex-Lytton) delivered double-digit growth.