Duke Energy Corp. and Progress Energy Inc. said Tuesday they had completed their merger now valued at about $32 billion to form the nation’s largest electric company. But the normally routine event came with a twist.

Bill Johnson, who was tapped to lead the combined company as president and chief executive, has decided to leave by “mutual agreement,” the companies said.

Duke CEO Jim Rogers, who was expected to be executive chairman, has instead been named CEO of the new company.

Whether it was Johnson or the company’s board that had a last-minute change of heart is unclear. But as late as Monday, Duke staffers were describing Johnson as the pending CEO and scheduling post-merger interviews for him as the top manager.

The company declined to answer questions about the switch.

Regulators probing JPMorgan over power

JPMorgan Chase has another headache.

Energy regulators are investigating whether the bank manipulated electricity markets in California and the Midwest, resulting in higher prices and possibly millions of dollars in improper payments to JPMorgan generators.

The Federal Energy Regulatory Commission said in court documents this week that bidding practices in JPMorgan’s commodities business “may have been designed to manipulate” the markets.

The regulators said they have been investigating JPMorgan since August.

The commission generally does not make investigations public, but on Monday it filed papers in federal court in Washington to try to force the bank to hand over 25 emails that regulators want to examine.

JPMorgan says the emails are privileged.

Spokeswoman Jennifer Zuccarelli said the bank believes that it has “complied in all respects with the law.”

“We welcome the court’s assistance in resolving this dispute over documents,” she said.

GM re-evaluating Facebook advertising

General Motors, which said it would stop advertising on Facebook on the eve of the social network’s initial public offering in May, is talking with the site about resuming the ads, two people familiar with the talks said.

Those efforts have included Facebook Chief Operating Officer Sheryl Sandberg talking with GM Chief Executive Officer Dan Akerson, said one of those people who asked not to be named because the discussions are private.

GM, which has an Allen County truck plant, said in May it decided to stop advertising on Facebook midyear after a regular spending review.

The Detroit-based automaker spent $10 million on paid ads on Facebook last year, a person familiar with the spending has said.

That’s a fraction of the about $1.8 billion GM spent in 2011 on advertising in the U.S., according to Kantar Media.

Peugeot may cut workforce by 10,000

Peugeot Citroen plans to shed as much as 10 percent of its French workforce this year, more than previously announced, as sales slide and management seeks further savings, a union official says.

“They will raise the job cuts target in France alone to 8,000-10,000,” Christian Lafaye, the head of Peugeot’s second-biggest union, said in an interview. Paris-based Peugeot, Europe’s second-largest automaker, said in November it aimed to reduce headcount by 6,000 in the region.