The rating action targeting the largest owner of Canada’s giant Syncrude oil-sands mining consortium comes amid a swoon in oil prices below $40 a barrel, which has eroded profit margins in the energy industry and made it more difficult for highly-levered oil producers to service their debt loads. Moody’s lowered its creditworthiness assessment of Canadian Oil Sands’ senior unsecured debt to Baa 3 from Baa 2 and kept its “negative” outlook for the Calgary-based company. Baa 3 is Moody’s lowest rung of investment-grade credit and just above the speculative, or junk, grade. “Moody’s expects negative free cash flow [at Canadian Oil Sands] of about 125 million Canadian dollars ($94 million) from June 30, 2015, to September 30, 2016, to be largely debt funded,” it said. The ratings action was prompted by the recent tumble in crude prices to more than six-year lows and Canadian Oil Sands’ deteriorating balance sheet. […]