Indian mining firm Adani has suspended two major contractors, Parsons Brinckerhoff and Korean construction company Posco, which are working on the A$16.5bn ($12.5bn) Carmichael coal mine in Australia.

The company’s latest move of dissolving the teams is raising speculation about the mega mining project.

The Guardian reported Adani as saying that the latest decision was linked to the suspension of engineering contractors in June.

Following the move, steelmaker Posco, which had been negotiating with Adani about taking equity stakes in the mine and rail link, will return to Korea.

Last month, Adani requested four major engineering contractors to halt work on projects that are around the Carmichael mine in Queensland.

The projects also includes a joint venture rail line, as well as the expansion of Abbot Point port.

According to sources, Adani suspended the work by WorleyParsons and Aecon, Aurecon and SMEC.

Located in the north of the Galilee Basin in Central Queensland, the proposed thermal coal mine Carmichael is expected to produce 60 million tonnes of coal annually.

Set to have an operating life of around 90 years, the mine is expected to extract four billion tonnes of coal resource.

Environmental groups opposed the mine, claiming that it will have a potential impact on the Great Barrier Reef.

Image: Satellite image of the Great Barrier Reef. Photo: courtesy of Nasa.