A look at this week's earnings from select utilities:
— Duke Energy Corp.'s earnings fell 42 percent in the first quarter because of cost overruns at a coal plant under construction in Indiana. The North Caroline company's underlying earnings grew slightly, despite a mild winter that reduced electric power demand. The company said its planned merger with Progress Energy, which would create the biggest U.S. utility, is on track to be completed July 1.
— Progress Energy's profit fell 19 percent as an unseasonably warm winter drove down power demand across the entire utility industry. The first three months of this year were, together, the warmest ever recorded nationwide. Maintenance at one of the North Carolina company's nuclear reactors also increased costs.
— Exelon Corp. of Chicago earned $200 million in the first quarter, although warm weather hurt revenue and profit at its power stations. Wholesale power prices were dragged lower by natural gas prices that have slipped to their lowest levels in a decade. In many parts of the country natural gas prices help determine the wholesale price of power.