Indian mining giant Adani has suspended two major contractors on its Queensland coal project, raising fresh speculation about the company's ability to finance Australia's largest coal mine.

Project managers Parsons Brinckerhoff and Korean construction company Posco, which is also touted as an investor in the final project, were told late last week to stop work on the Carmichael mine, rail and port project.

Adani insisted on Tuesday that the mine would still go ahead and it was not pulling out of Australia. Credit:Glenn Hunt

Company sources said senior Adani executives flew to India at the weekend for talks about the project's future.

It comes less than a month after Adani stood down four engineering firms – WorleyParsons, Aecon, Aurecon and SMC – and scores of workers involved in preparatory works on the development, which would open up Queensland's vast Galilee Basin.