Australian-listed Centennial Coal is seeking a declaration that Swiss trader Glencore’s use of cash-settled swaps to secure more than 5% of Austral's shares was unacceptable. Glencore owns 7.4% of Austral directly and controls a further 6.5% through cash-settled swaps.

Centennial has sought a declaration of unacceptable circumstances and interim and final orders. It has also asked the panel to order the shares covered by the swaps be tendered into Centennial’s bid.

In a hearing last month, the panel denied Glencore’s request to declare unacceptable circumstances over action taken by Centennial. Glencore claimed Centennial’s bid invalid because it had not disclosed plans to shut the Munmorah mine.

The Takeovers Panel ruled on May 23 that Munmorah’s planned closure was not material to Austral shareholders' decision on the bid.

Though Centennial's shares took a hit following the April 29 announcement Munmorah would be closed, the price has firmed at $A5.13.

If the panel rules the swaps must be unwound this would lift Centennial's stake in Austral above 90%, compelling Glencore to sell its remaining shares.

Cash-settled swaps – commonly used as financial hedging tools - are sometimes used to hide stakes in listed companies in the lead-up to a takeover bid.