Adani Mining has signed up buyers for around 70 per cent of the coal it plans to produce from a huge mine in Australia, putting it a step closer to being able to seal funding for the A$10 billion ($7.9 billion) project, its local head said on Thursday.

The key hurdle Adani needs to clear to secure loans for the Carmichael mine, rail and port project is dredging approval to expand its Abbot Point port. Australia's environment minister is expected to rule on that in the second half of this year.

($1 = 1.2644 Australian dollars)