General Electric said it is dealing with a ‘very challenging environment.’ The global oil-market rout continued to weigh on General Electric Co. GE -0.71 % , which posted a quarterly decline in operating income and orders for its core industrial businesses. GE reported a 6.1% gain in revenue for the first three months of 2016, but profit declines in units making locomotives, power turbines and oil-industry equipment hurt its bottom line. Chief Executive Jeff Immelt said the conglomerate’s diversity enabled it to withstand a “very challenging environment,” especially in the oil and gas business. The company maintained its annual guidance for investors but lowered its outlook for the oil unit, saying its operating profit could fall 30% over the course of 2016 on as much as a 20% drop in revenue. “Diversity is a key strength during this period of volatility,” Mr. Immelt said on a conference call. “Most […]