Closing the gap with the big two of Newmont and Barrick is considered vital if Placer is to continue to command the attention of gold-equity investors in the North American market, the world's biggest. Placer claimed yesterday that the offer was a "compelling opportunity" for Aurion shareholders. It said there was "strong strategic rationale" for the takeover given that it was the operator at two of Aurion's key assets, the Granny Smith and Porgera joint ventures, and claimed $US25 million ($A44.9 million) in annual post-tax synergies would flow to the combined group.