Chesapeake Energy Corp., the U.S. energy explorer battered by collapsing natural-gas prices and growing investor mistrust, will replace almost half its board under pressure from billionaire investor Carl Icahn.

Four of the company's eight non-executive directors will be replaced with nominees of the largest shareholders, Southeastern Asset Management Inc. and Icahn, Chesapeake said in a statement today. Icahn triggered the overhaul by acquiring a 7.6 percent stake last month to rein in what he saw as Chairman and Chief Executive Officer Aubrey McClendon's risk-taking and overspending that led to a $22 billion cash crunch and has eroded the share price by nearly 30 percent this year.

McClendon has been under a cloud since a series of media reports in March and April about personal loans he obtained using minority stakes in company-owned wells that he'd been allowed to gather for his private portfolio. The company announced May 1 that he will step down as chairman when a replacement is chosen.