Canada's Brookfield Asset Management Inc has purchased nearly 15 percent of Australian ports and rail operator Asciano Ltd as part of an agreed $6.5 billion takeover that has raised antitrust regulators' eyebrows, The Australian Financial Review (AFR) reported. The report comes just days after Asciano's domestic rival Qube Holdings Ltd and partners said they had bought a one-fifth stake in the target, and wanted to buy assets that may be up for grabs as the deal unfolds. The AFR reported Brookfield Infrastructure Partners, a subsidiary of Brookfield Asset Management, has acquired 146 million shares, or a 14.99 per cent stake, in Asciano at A$8.80 apiece. Asciano shares closed on Thursday at A$8.28. Brookfield intends to buy at least 50.1 per cent of Asciano, the AFR reported. The report come less than a month after the Australian Competition and Consumer Commission (ACCC) raised antitrust concerns over what would be the country's biggest inbound deal in four years, saying competition could be threatened by Brookfield already owning railways Asciano's trains run on. A spokesman for Brookfield could not be reached for immediate comment. Asciano officials did not respond to email messages and voicemail left outside normal business hours.