(Adds details on the deal, companies)
By Greg Roumeliotis and Mike Stone
May 5 (Reuters) - Mexican conglomerate Alfa Sab de CV and Harbour Energy Ltd have agreed to acquire Canadian oil and gas company Pacific Rubiales Energy Corp for C$6 billion, including debt, a person familiar with the matter said on Tuesday.
Pacific Rubiales is the largest independent oil and gas producer in Latin America. Its shares have plummeted more than 80 percent since oil prices began to slide last summer. Alfa, which already owns a 20 percent stake in the company, decided now was the time to pounce.
Alfa and Harbour have agreed to pay around C$6 ($5) per share for Pacific Rubiales and will each own half of the company, the person said, asking not to be identified because the deal is not yet public. Pacific Rubiales ended trading on Tuesday at $C4.83.
Harbour Energy is a joint venture between Asian commodity trader Noble Group Ltd and U.S. private-equity firm EIG Global Energy Partners.
Alfa believes the investment, by boosting its oil and gas footprint, will position it to participate more strongly in Mexico's energy liberalization, the person added.
Representatives for the companies did not immediately respond to requests for comment.
Toronto-Based Pacific Rubiales produces natural gas and crude oil at 90 exploration and production blocks in seven countries; Colombia, Peru, Guatemala, Brazil, Guyana, Papua New Guinea and Belize.
Alfa, headquartered near Monterrey, Mexico, has businesses in oil and gas, branded foods, aluminum auto components, petrochemicals, information technology and telecommunications services. It has a market capitalization of 164.7 billion Mexican pesos ($10.6 billion).
Bank of America Corp advised Pacific Rubiales on the deal. (Reporting by Greg Roumeliotis and Mike Stone in New York; Editing by Christian Plumb)