(Bloomberg) — Shell Plc (SHEL) agreed to buy Canadian producer ARC Resources Ltd. (ARX.TO) for $13.6 billion, its biggest deal in more than a decade as it seeks to bolster fossil fuel reserves. ARC’s shares surged while Shell’s dipped. ARC has a high-quality, low-cost shale gas and liquids base that complements Shell’s existing operations in Canada, the London-based company said in a statement. With no significant acquisitions since Chief Executive Officer Wael Sawan took the helm, Shell’s efforts to r ...