Burger King Corp. said Friday that its chairman and chief executive is resigning to return to running his private equity firm, ahead of the anticipated initial public offering for the No. 2 hamburger chain.

Greg Brenneman is returning to TurnWorks Inc. to pursue business turnarounds. He joined Burger King in August 2004 to lead a turnaround after a period of slumping sales. The privately-held chain has had eight consecutive quarters of sales growth at stores open at least a year.

Burger King said that John Chidsey, 43, the company's president and chief financial officer, has been named chief executive, effective immediately. The company's board also announced that Brian Swette, a current independent director, would serve as non-executive chairman.

The management shake-up comes as the chain is preparing for its IPO, announced in February. Burger King hopes to raise up to $400 million in the stock sale, but has released few other details, such as the price per share or when it would occur.

"As the company enters this important next phase, the board and I discussed the commitment necessary for any CEO in a public environment and my career and family goals," Brenneman said in a statement. "As a result, together we decided that the best time to transition leadership was prior to Burger King's initial public offering."

In a statement, the board of directors said: "We are extremely pleased with the progress Burger King has made under Greg's leadership. He told us when he came that he wanted to transition the leadership of the company to John Chidsey at some point."

Burger King spokeswoman Edna Johnson declined further comment. The chain is second only to McDonald's Corp. among hamburger restaurant chains.