Alliance Airlines (QQ, Brisbane International) has confirmed a charter contract with OZ Minerals, a copper-focused international company based in South Australia, will end during the third quarter of the year.

An airline filing with the ASX Exchange on Tuesday, April 18, states the last flight to the mining firm's copper/gold Prominent Hill site will operate on August 11.

Alliance Airlines said revenue arising from the OZ Minerals’ contract during the last 12 months had accounted for 5.8% of its total revenue and had been forecast to reduce significantly during the 2018 Financial Year.

"The contract also provides Alliance with a significant exit fee to further offset any future financial impact," it noted.