NEW YORK ( TheStreet) -- Chesapeake Energy's ( CHK) board and CEO roles are now split after the company's co-founder and chief executive Aubrey McClendon was replaced as chairman by former ConocoPhillips ( CHK) chair Archie Dunham. The move is the biggest change in a sweeping overhaul of the struggling gas giant's board announced in June and put in place on Thursday. Chesapeake Energy also said it elected four other independent members to its nine-member Board of Directors ,including three proposed by the company's largest shareholder Southeastern Asset Management and one proposed by activist investor Carl Icahn who recently took a large stake in the Oklahoma City-based oil and gas driller. Southeastern Asset Management has elected Bob Alexander, Brad Martin and Frederic Poses to Chesapeake's board, while Icahn has nominated Vincent Intrieri. Those elections and Dunham's replacement of embattled CEO McClendon as chairman come as a quick response to Southeastern and Icahn's calls for changes to Chesapeake Energy's board that will help the company better manage its finances as a cash crunch looms. After director Charles T. Maxwell retired from Chesapeake's board at the company's June 8 annual meeting, Richard Davidson, Kathleen M. Eisbrenner, Frank Keating and Don Nickles have resigned. Earlier in June, the New York City comptroller had asked for the removal of Oklahoma State University President Burns Hargis and former Union Pacific Chairman Richard K. Davidson as directors. Hargis and Davidson resigned after they weren't re-elected by shareholders at Chesapeake's annual meeting. Of the changes, Chesapeake CEO McClendon welcomed new board members to help on the execution of, "our common mission to deliver to our shareholders the substantial net asset value we have created in the past seven years as Chesapeake has helped lead the unconventional resource revolution in the energy industry," in a press release. "We believe this board will prudently guide, assist and complement management's efforts to capture its potential," said Southeastern Asset Management chairman Mason Hawkins in a press release. "Chesapeake is now heading in the right direction. With the Board providing strong oversight, the management team will be sharply focused on realizing the value of its assets and the company will be well positioned to create substantial value for shareholders going forward," added Icahn in a statement.