(Adds strategist quotes and details throughout; updates prices) * Loonie weakens 0.3% against the U.S. dollar * Canadian producer prices rise 14.2% year-over-year in April * Price of U.S. oil settles 3.4% lower * Canadian 10-year yield eases 3.2 basis points to 1.569% By Fergal Smith TORONTO, May 13 (Reuters) - The Canadian dollar weakened against its U.S. counterpart on Thursday, pulling back from a six-year high the day before, as oil tumbled and Bank of Canada Governor Tiff Macklem said further appreciation of the currency could weigh on the economy. The Canadian dollar fell 0.3% to 1.2164 to the greenback, or 82.21 U.S. cents, having traded in a range of 1.2104 to 1.2202. On Wednesday, it touched its strongest intraday level since May 2015 at 1.2042 If the buoyant Canadian dollar continues to rise, it could create headwinds for exports and business investment as well as affecting monetary policy, Macklem said. "I think the comments from Macklem were overdue," said Amo Sahota, director at Klarity FX in San Francisco. "There will be boardroom discussions (at exporters) about what do we do if CAD keeps appreciating." The loonie has been on a tear since the Bank of Canada last month shifted to more hawkish guidance and cut the pace of its bond purchases. The recent surge in commodity prices has also bolstered the currency. Canada is a major producer of commodities, including oil. U.S. crude oil futures settled 3.4% lower at $63.82 a barrel as India"s coronavirus crisis deepened and a key U.S. pipeline resumed operations, halting a rally that had lifted crude to an eight-week high. Canadian producer prices rose by 14.2% year-over-year in April, the biggest increase since February 1980, led by lumber and other wood products, a flash estimate from Statistics Canada showed. On Friday, Canadian manufacturing sales and wholesale trade data for March are due for release. Canadian government bond yields eased across a flatter curve, tracking the move in U.S. Treasuries. The 10-year was down 3.2 basis points at 1.569%, having pulled back from an earlier eight-week high at 1.624%. (Reporting by Fergal Smith; Editing by Bernadette Baum and Peter Cooney) Our Standards: The Thomson Reuters Trust Principles.