Oslo-listed Klaveness Combination Carriers (KCC) has clinched a long-term deal to carry caustic soda for Australian mining and metals company South32.

The combination carrier owner has signed a six-year contract of affreightment (COA) for shipments on its Cleanbu-class vessels from South32's Worsley Alumina refinery in Western Australia.

No financial details have been released, but the companies said the deal establishes a framework for how they will work together to deliver further reductions in carbon emissions in the trade.