McClendon has been a tireless promoter of gas as an alternative to coal and Middle Eastern oil imports. Using cutting-edge drilling techniques in domestic shale formations overlooked by major international energy giants, he built Chesapeake into what was at one time the largest U.S. gas producer.
McClendon oversaw a 500-fold increase in Chesapeake's market value from its 1993 debut as a public company to a peak of $35.6 billion in June 2008, according to data compiled by Bloomberg. Since then, stung by cratering gas prices and growing investor mistrust, the company's value fell by more than half to about $13.6 billion.
Chesapeake agreed to sell $12 billion in pipelines, oilfields and other assets in 2012, short of McClendon's original sales target, as a cash flow shortfall threatened to derail drilling plans and erode the company's compliance with lending covenants.
The new permanent CEO will inherit a $4 billion to $7 billion asset-sales target for this year and the unfinished task of converting a company that pumps enough gas to supply 20 percent of American household demand into a producer of crude and gas by-products such as propane.
Icahn and Hawkins, who together control 22 percent of Chesapeake's stock, pushed for McClendon's resignation after concluding his presence and the controversy surrounding his personal business deals was hurting the company's share price, a person with knowledge of the discussions said in January.
As one of the first explorers to embrace horizontal drilling and hydraulic fracturing, McClendon helped usher in a revival of U.S. gas and oil production with discoveries such as the Haynesville Shale in Louisiana and Utica Shale in Ohio.
The success of the drilling methods led to a glut of North American gas that drove prices to a 10-year low in early 2012, prompting Chesapeake to cut jobs, curtail capital spending and offer oilfields and other assets up to the highest bidders.