GlaxoSmithKline has paid A$20m (£9.75m) in a final settlement to Biota, the Australian biotech business that sued the UK-based pharmaceuticals company for allegedly failing to make sufficient efforts to market Relenza, its flu drug.

The payment will be a disappointment to shareholders in Biota, which began litigation in 2004 and sought up to A$430m in damages after claiming that GSK had not met the conditions in its licensing agreement to use “best endeavours” in selling the medicine.