Warren Buffett buys stake in Calgary's Suncor

Warren Buffett has bought into the Alberta oilsands with a stake inSuncor Energy Inc., according to a Securities Exchange Commission filing released today.

Buffetts Berkshire Hathaway Holdings owned 17.8 million Suncor shares on June 30, a stake valued at more than $500 million in the Calgary-based heavy-oil producer.

The same regulatory filing revealed Buffett made a larger investment in General Motors and added to its holdings in U.S. Bancorp and Wells Fargo & Co.

Suncor stock rose$1.18 cents to $34.97 in trading today.

Shares of companies often rise after Berkshire discloses sizeable new investments because investors try to copy Buffett, who has an enviable record as a successful investor.

Buffett, 82, is legendary for his ability to pick value stocks and apply common sense to the markets.

Buying into Suncor puts him into the midst of the debate over the rapid pace of oilsands production, which has been questioned by environmentalists as harmful to the environment, and over the Keystone pipeline which would take Alberta oil south to the U.S.

• Enforcement lacking in oilsands infractions, study finds

The company derives most of its current production from Alberta's oilsands andplans to expand there. It also owns several refineries to process its crude.

Analysts say Suncor isnt waiting on a decision over controversial pipelines such asKeystoneto transport its oil as it has booked pipeline and rail capacity for the next several years.