Clayton Utz has set new standards in Australian contract law in negotiations for the Australian Rail Track Corporation's (ARTC) A$1.4bn (£590m) upgrade of the country's Melbourne to Brisbane rail network.
Clayton Utz infrastructure partner Murray West described the contracts - worth A$720m (£303.4m) - as "fairly unique contracts involving innovative risk-sharing arrangements".
ARTC kept secondary bidders on hold during negotiations with the preferred consortia to speed them up.
West said: "Rather than following a rigid format, the contracts are designed to be flexible, with the aim of keeping costs down and incentives up, so all parties are motivated to bring the projects in ahead of time and budget."
Clayton Utz is also advising on negotiations for a A$250m (£105.4m) advanced management and safety system, a A$192m (£80.9m) development of the Southern Sydney Freight Line and a A$60m (£25.3m) communications system.
Australian firms Freehills, Malleson Stephen Jacques and Phillips Fox advised the consortia alongside in-house counsel.