A Chinese steel maker and Australian iron ore explorer have extended their joint venture with plans to develop South Australia’s first port capable of handling super-large bulk carriers.

Australian Securities Exchange-listed Centrex Metals on Monday said it had signed a joint venture agreement with a subsidiary of Wuhan Iron and Steel Company Ltd (WISCO) for the development of a new iron ore export port at Port Spencer, northeast of Port Lincoln on Eyre Peninsula.

The companies already have a joint venture to develop magnetite iron ore mines and a processing plant to the west of the Port Spencer site.

The port will be the first in the state to allow the direct loading of Cape-size ships, which hold up to 200,000 tonnes, and will be used to export product from the joint venture’s planned new mines.

WISCO and Centrex expect to start exporting from the port in early 2015.

Centrex managing director Jim White said decisions to proceed with the port, as well as a first mine and a processing plant, were all expected to be made late this year or early next year.

“We see today’s port joint-venture announcement as a real stepping stone to a substantial new economic, resources and infrastructure era for southern Eyre Peninsula,” Mr White said in a statement.

Separately, other mineral explorers planning iron ore mines in the Braemar region to the east, including Carpentaria Exploration and Havilah Resources, have called for a new port facility near Port Pirie.

The SA government said in a recent report that there was overall uncertainty regarding access and capacity of existing, new and proposed port infrastructure in the state.

SA Chamber of Mines and Energy chief executive Jason Kuchel last month said many companies were unable to finalise their mine without a port to get product to market.

Conversely, infrastructure providers were unable to fund a port without the mines already being in place.

Mr Kuchel has called for government intervention to end the current piecemeal approach to infrastructure development in the state.

Shares in Centrex closed up half a cent, or 1.69 per cent, at 30 cents on Monday.