9:15 p.m. | Updated
HOUSTON — Aubrey K. McClendon, Chesapeake Energy’s daring and innovative co-founder, will step down as chief executive on April 1 after months of scrutiny over how he mixed his personal finances and those of the corporation.
Mr. McClendon’s retirement, announced by the company on Tuesday, comes as the national boom in natural gas drilling, which he helped set in motion, is fading, diminishing Chesapeake’s prospects.
Over the past decade, Mr. McClendon aggressively explored for gas and outbid competitors in one shale field after another. Not only did his small Oklahoma company become the nation’s second biggest gas producer after Exxon Mobil, but Mr. McClendon also assembled a trophy room of assets that included a piece of the Oklahoma Thunder basketball team, a winery and a $12 million collection of antique maps.
In the end, a downturn in natural gas prices, caused in large part by the industry’s exuberant drilling, dealt a huge blow to the company’s balance sheet and to Mr. McClendon’s personal fortune.
Mr. McClendon borrowed heavily — more than $800 million — to finance his participation in an unusual compensation plan that allowed him to invest alongside his company in every well it drilled, sharing both in profits and expenses. Last year, the Securities and Exchange Commission opened an inquiry into Mr. McClendon’s finances, and a shareholder rebellion led to his removal as chairman in June and a reshuffling of the board.
Chesapeake, which borrowed extensively to finance its expansion spree, has been forced to unload $12 billion in valuable oil and gas fields over the last year as it tried to pay off its crushing debts. Last September, the company still had $19 billion in debt, according to Philip Weiss, a senior oil company analyst at Argus.
“He really built this company from nothing and made it into something meaningful,” Mr. Weiss said, “but in the end, I think it’s the right thing for the company and its shareholders” for him to leave. “The company needs a financial guy to bring spending under control.”
Investors appeared to agree, sending Chesapeake’s shares up more than 10 percent in after-hours trading.
The roots of Mr. McClendon’s sudden departure lay partly in a shake-up of Chesapeake’s board last summer, in which the company replaced more than half of its directors. Four of those board members were nominated by two major investors, Southeastern Asset Management and the investor Carl C. Icahn; an independent chairman was also appointed.
In recent weeks, Chesapeake’s board concluded that the company’s stock was suffering from Mr. McClendon’s presence, according to a person briefed on the matter. Shares in the company have fallen 14 percent over the last 12 months.
“Aubrey and the board have agreed that the time has come for the company to select a new leader,” Chesapeake’s chairman, Archie W. Dunham, said in a statement.
The company said the board’s review of Mr. McClendon’s financial dealings “to date has not revealed improper conduct.”
Mr. McClendon, 53, agreed to retire from the company on April 1 and will continue serving as chief executive until a successor is appointed.
“I am extremely proud of what we have built over the last quarter of a century,” he said in a statement. “While I have certain philosophical differences with the new board, I look forward to working collaboratively with the company and the board to provide a smooth transition.”
When gas prices were still high four years ago, Chesapeake’s stock price soared, and Mr. McClendon had a net worth of more than $1 billion. He bought homes in Hawaii, Colorado and Bermuda.
But as the price of gas fell by more than two-thirds over the last few years, Chesapeake lost more than two-thirds of its value as well.
Pressure on Mr. McClendon began last April after news reports revealed that he had obtained personal loans using minority stakes in company-owned wells as collateral. Reuters reported that he had personally borrowed more than $1 billion from EIG Global Energy Partners, a firm that also invested in Chesapeake, raising questions over conflict of interest.
Mr. McClendon was a larger-than-life figure in an industry filled with them. His dealings stretched across the globe as he negotiated partnerships with the Norwegian oil company Statoil, China’s CNOOC and France’s Total, shepherding the foreign oil giants into joint ventures in shale fields around the country.
“It’s an end of an era,” said Fadel Gheit, a senior oil analyst at Oppenheimer. “He was a maverick in the true sense of the word, and he represented both the good and the bad in corporate America. He was the risk-taker, a true visionary, but obviously there were excesses.”
Mr. Icahn, now one of the company’s largest shareholders, was generous in his praise.
“Aubrey has every right to be proud of the company he has built, the world-class team of people at Chesapeake and the collection of assets he has assembled, which in my opinion are the best portfolio of energy assets in the country,” he said.