The consortium, made up of Qube Holdings, Global Infrastructure Partners and Canada Pension Plan Investment Board, has made a "non-binding indicative proposal" to acquire all of the issued share capital of Asciano that it does not already own, at a value of A$9.25 per share.
The Qube bid came one day after Brookfield Asset Management made a bid worth A$9.22 per share.
The Asciano Board is considering the proposal, but said that it will continue to recommend the offer from Brookfield.
The Australian Competition and Consumer Commission (ACCC) has expressed concerns about the Brookfield bid, saying that it could lead to lower competition in the supply of rail haulage services in Western Australia
Qube Holdings said in its statement that it does not need ACCC approval for a takeover of Asciano.
The Qube consortium currently owns 19.99% of Asciano, bought in October. This was in response to a previous Brookfield takeover bid which required 75% shareholder approval. The consortium said at the time that it "[did] not support the current Brookfield scheme proposal and [did] not intend to vote in favour of it".
Last week, Brookfield bought 14.9% of the port company's shares last week, together with an arrangement that allows it to control another 4.3%. Its latest takeover bid only requires 50.1% approval.
Melbourne based infrastructure expert Simela Karasavidis of Pinsent Masons, the law firm behind Out-Law.com said that Qube Holding's move is "an interesting development – it highlights the potential trade-off between price and execution certainty".