Canadian energy company Athabasca Oil Corp. said it scaled up its portfolio in heavy oil in a $435 million deal with Norwegian energy major Statoil.

The Canadian subsidiary of Statoil confirmed the sale of its entire holdings in an oil sands project in the province of Alberta to Athabasca.

"This transaction is transformational for Athabasca and establishes scale with top tier thermal assets and people," Athabasca President and CEO Robert Broen said in a statement. "Athabasca has the financial strength to drive oil weighted growth at competitive metrics in the current environment."

Athabasca said the cash deal extended to the Leismer thermal oil project, which is currently producing about 24,000 barrels of oil per day. The company said the deal gives it a stronger base of production of around 40,000 barrels of oil equivalent estimated for next year.

The Norwegian company took full ownership of the Leismer oil sands project in Canada in 2014. Critics of Canadian oil sands production argue its more carbon intensive to produce than other lighter crude oil grades. A steam injection method used by rival Canadian Natural Resources Ltd. to warm viscous oil ran out of control two years ago, causing long-term seepage in Alberta.

Statoil said Leismer reached a record level of production at the end of 2014 with 20,000 bpd. Both companies said the project has enough reserves in pace to keep production static for the next 30 years.

The transaction with Athabasca covers an undeveloped project and other infrastructure assets tied to Leismer. Statoil said the deal is part of its effort to optimize its portfolio by focusing on core activities, which include assets offshore Newfoundland.

Statoil said expenses tied to exploration increased by $170 million to $581 million, while adjusted earnings declined 69 percent year-on-year to $636 million.