As they guided Europe’s largest oil companies through the industry’s worst slump in two decades, the bosses of Royal Dutch Shell Plc and BP Plc had a simple message for investors: we’ll protect the dividend at all costs. Not everyone is convinced they’ll be able to keep their word. Even after they raised billions of dollars by cutting costs, selling assets and adding debt, cash is pouring out of both companies in the form of hefty shareholder dividends. Yields on those payments — which fell through 2016 as crude started to recover — have risen this year, typically a signal that investors fear a cut in payouts. “BP and Royal Dutch Shell have unsustainable dividends,” Neil Woodford, head of investment at Woodford Investment Management Ltd. who manages about $20 billion, wrote in a blog . “These companies are liquidating themselves rather than facing up to the need for a […]