In a separate statement, Air Canada, the country's largest carrier, said Aimia rejected its original bid.

Aimia said it proposed a revised offer of $450 million for the program to Air Canada and its partners, Toronto-Dominion Bank, Canadian Imperial Bank of Commerce and VISA Canada Corp.

In late July, Air Canada, two Canadian banks and Visa offered to buy back the carrier's previous Aeroplan frequent flyer program from Aimia, setting an Aug. 2 deadline. The bid included C$250 million in cash and the assumption of approximately $2 billion of Aeroplan points liability.

Earlier on Thursday, a spokeswoman for Montreal-based Aimia said by email the company is in talks with the Oneworld airline alliance, including American Airlines and Cathay Pacific as a "potential preferred airline partner for Aeroplan." Air Canada is a member of Star Alliance which is a competitor to Oneworld.

Air Canada spun off Aeroplan in 2002 to data analytics firm Aimia. But earlier this year, Air Canada said it would launch its own loyalty program.

The partners offered Aimia shareholders $3.64 per share for Aeroplan, a premium of 45.6 percent to Aimia stock's closing price on July 24.

But news in May 2017 that Air Canada would start its own frequent-flyer program to replace Aeroplan hit Aimia's stock, which plummeted around 60 percent in one day.

Air Canada CEO argued in late July that it's not a "hostile bid," although some investors argue that Aimia may have little choice but to accept it.

"Aimia is trying everything it can to get the price up a little bit," said Greg Taylor, a portfolio manager at Purpose Investments which doesn't hold any shares in either company. "But Air Canada is the one that has the most synergies. So, the Air Canada, CIBC, TD bid is going to be hard to beat and I think this really just feels like Aimia trying everything in their power to get a white knight bid to get the price a little higher."

(Reporting by Allison Lampert in Montreal and Diptendu Lahiri in Bengaluru; Editing by Sandra Maler)