Energy pipeline and storage companies were one of the hottest investments on Wall Street, offering steadily higher payouts, tax benefits and insulation from wild swings in oil prices. Now, investors are contending with a sharp selloff in master limited partnerships that has outpaced the fall in oil prices . Deal making in the sector has slowed and investors say they are calling into question the ability of MLPs to keep up the steady pace of payout increases as U.S. oil output finally starts to decline. The yearslong boom in U.S. oil production fueled the proliferation of MLPs. The companies transport, store, produce and refine energy, passing on the bulk of their earnings to shareholders. Income-starved investors flocked to the sector, lured by the companies’ assurances of steady payout increases and their tax advantages. Since 2009, MLPs have raised more than $100 billion from initial public offerings and follow-on stock […]