Suncor EnergyExxon wasn't the only energy name that Berkshire picked up last quarter -- Suncor Energy ( SU) was another. Buffett and company bought 240,500 shares of the Canadian oil firm, building its stake in the stock to $644 million. >>5 Stocks Under $10 Set to Soar Suncor is the biggest oil and gas name in Canada, with 550,000 barrels of oil equivalent coming out of the ground every day. The firm is a major oil sands operator, exposure that the firm was able to acquire relatively cheaply and is now leveraging for bigger margins than most of its peers. Investments in new extraction technology have helped to bust through plateaus in production at SU's oil projects, squeezing more cash from older assets. Like Exxon, Suncor is an integrated energy firm. That means that the company is involved with every step of the process, from pulling commodities out of the ground to transporting, refining, and retailing fuel at Petro-Canada gas station locations. While operations downstream are dilutive to margins (holding SU's net profit margins sub-10%), they give the firm a heftier top-line than a standalone E&P stock would have. Despite the upside, Suncor isn't a very exciting energy name; investors are better off in Exxon.