CALGARY — Canadian Oil Sands Ltd., the largest partner in the massive Syncrude Canada Ltd. oilsands mine, posted second-quarter earnings Tuesday that missed analyst expectations, and announced the retirement of its CEO.Profits during the quarter were $219 million, or 45 cents per share — well short of the 53 cents per share analysts had on average been expecting, according to data compiled by Thomson Reuters.But the profits were more than double the $101 million, or 21 cents per share, the Calgary-based company booked during the same period a year earlier.Sales were $921 million, up from $740 million.CEO Marcel Coutu — who is set to retire as of January 1, 2014 — attributed the higher earnings to better-than-expected oil prices and a favourable exchange rate.Also Tuesday, Canadian Oil Sands reduced its targeted 2013 production range for the second time this year.Earlier this year, it had lowered its target by five per cent to between 100 and 110 million barrels. And now, it said it is expecting production to range between 100 and 104 million barrels.Production at Syncrude averaged 273,100 barrels per day during the quarter, an improvement from 238,500 barrels per day a year earlier.Coutu has been at the helm of Syncrude since August 2001, and over his tenure grew the company from a $2-billion income trust to a corporation with a stock market value of $10 billion“I have been fortunate and proud to lead COS through the economic and commodity cycles of the past decade,” Coutu said in a release.“With this solid asset base, a talented management team and the approaching completion of Syncrude’s major sustaining projects, I believe COS is well positioned for continued success. It’s therefore a good time for me to pass the leadership of this great company on to a successor.”The company’s board has begun a search for Coutu’s successor. Coutu has agreed to stay on in a consulting role for a year after his retirement to ensure the transition goes smoothly.Canadian Oil Sands is best known for its 37 per cent stake in the large Syncrude mine north of Fort McMurray, Alta. It’s one of the oldest and largest projects of its kind.The other owners of Syncrude include Imperial Oil Ltd. (TSX:IMO), Suncor Energy Inc. (TSX:SU), Chinese firms Sinopec and CNOOC, Mocal Energy and MurphyOil.Bitumen from Syncrude is upgraded into a more valuable product called synthetic crude oil, which refineries can more easily handle.