Suncor sold the assets for $1 billion to CQ Energy Canada Partnership, which includes Britain‘s Centrica PLC and Qatar Petroleum International.
The deal includes conventional properties throughout Alberta, northeastern British Columbia and southern Saskatchewan.
Production from the assets is estimated to be about 42,000 barrels of oil equivalent per day this year.
Suncor has said it will adjust its guidance accordingly once the deal closes.
The Calgary-based company said it would direct the proceeds from the sale toward three priorities: investing in its base business, pursuing profitable growth projects and returning cash to shareholders through dividends or share buybacks.
Suncor has sold billions in assets in Canada, the U.S. and around the world since it merged with Petro-Canada in 2009, as it focuses on its core oilsands business.
Under the deal initially announced in April, Centrica will own 60 per cent of the newly acquired business and operate it, with its Qatari partner owning the rest.
Centrica owns the Direct Energy business that operates in all 10 Canadian provinces and most of the United States.
A Centrica subsidiary bought the Wildcat Hills property northwest of Calgary from Suncor for $375 million.