MONTREAL - Quebec pension fund manager, The Caisse de depot, says it is buying a 26.7-per-cent stake in Australia's Port of Brisbane, reportedly for nearly $1 billion.

The institutional investor is purchasing the interest held by Global Infrastructure Partners, a New York-based private equity firm that specializes in infrastructure investments, following a bidding process launched earlier this year.

The Caisse says a confidentiality agreement prevents it from disclosing the purchase price. But Bloomberg, citing sources, reported the transaction is valued at AU$1 billion ($960 million.)

Macky Tall, the manager's senior vice-president of infrastructure, called the acquisition a "first-class asset," adding that the investment will "step up" its presence in the resilient market and diversify its portfolio.

Australia's third-largest port was privatized in 2010. It handles more than 37 tonnes of international cargo annually valued at around $50 billion. It is also the closest major container port to Australia's largest trading market in the Asia-Pacific rim.

The transaction is expected to close by Dec. 18.