The $350-million sale of a 35% stake in the Senegal oil field by ConocoPhillips in 2016 was challenged by FAR at the International Chamber of Commerce.
FAR said it was going through the arbitration award. It holds a 15% stake in the Sangomar oilfield that also counts Cairn Energy Plc as a stakeholder.
Woodside had no immediate comment.
Shares of FAR slumped nearly 9% in early trade to A$0.031 - their lowest level since the middle of 2013.
(Reporting by Nikhil Kurian Nainan in Bengaluru; Editing by Sriraj Kalluvila and Shailesh Kuber)