Genesee & Wyoming provided better terms and conditions for the sale of its Australian rail business to Macquarie Group than it did to Aurizon after putting the rail assets on the block for $627 million, the Queensland rail company has alleged.

Aurizon filed a claim with the NSW Supreme Court in mid-September alleging US-headquartered G&W breached agreements when it arranged to sell its Australian rail assets to Macquarie Infrastructure and Real Assets (MIRA) and Dutch pension fund PGGM after striking a $US8.4 billion ($12.2 billion) deal in July to be acquired by Brookfield Infrastructure and GIC.