Australian ports and rail operator Asciano said Wednesday it had received an Aus$8.8 billion (US$6.8 billion) takeover offer from Canada-based Brookfield Infrastructure Group and was considering the proposal.

Asciano said the cash and stock offer valued its shares at Aus$9.05. The stock surged more than 20 percent when a trading halt was lifted and ended 16.8 percent higher at Aus$7.77.

"The board of Asciano, together with its advisers, concluded that it was in the interests of its shareholders to engage further with Brookfield on an exclusive basis to progress the proposal," the company said in a statement.

"Discussions are at a very early stage and a number of significant steps need to be undertaken in order to progress to a formal proposal from Brookfield."

The proposal, subject to Brookfield's due diligence, would be by scheme of arrangement, meaning only 50 percent of shareholders must support the deal for it to go ahead.

It would also need the approval of the Australian Competition and Consumer Commission and the Foreign Investment Review Board.

"If the proposal does not proceed, the board believes that Asciano has a very attractive independent future and that the company is well positioned to continue to deliver strong growth," Asciano added.

The bid came two months after shareholders of Australian logistics firm Toll Holdings voted in support of a Aus$6.49 billion (US$5 billion) takeover bid by Japan Post.