(Reuters) - Billionaire investor Carl Icahn revealed a 7.6 percent stake in oil and gas company Chesapeake Energy Corp and called for the company to replace at least four of its directors, saying the board has failed "in a dramatic fashion" in its oversight of management.

The corporate-raider-turned-activist investor asked the company for two board seats for his own representatives and two for another large shareholder such as Chesapeake's largest shareholder Southeastern Asset Management.

"This board has led the company through a highly publicized spate of corporate governance breakdowns while amassing an astounding $16 billion funding gap, which we believe has contributed to the share price decline of over 55% from the 52-week high," Icahn wrote in a letter to the company.

Icahn holds 50.1 million shares in the company, according to a regulatory filing. That would make him the third largest shareholder in the company, according to Thomson Reuters data.

Chesapeake did not immediately comment on Icahn's stake.

(Reporting by Michael Erman and Matt Daily in New York, additional reporting by Divya Lad in Bangalore; Editing by Sriraj Kalluvila)