Updated from 7:32 a.m. ESTThe Kieran Burke era has ended at amusement-park operator Six Flags ( PKS). Burke, the CEO targeted in a proxy fight by major holder Dan Snyder, was replaced by Snyder loyalist and former ESPN executive Mark Shapiro, the company confirmed Wednesday. The ouster, which was first reported by the Wall Street Journal, followed Burke's unsuccessful efforts to find a buyer for the company. "Six Flags announced today that the deadline for submission of final bids in its sale process has passed without any formal bids being received. The board of directors has unanimously ended the sale process," the company said. Three new directors have been appointed to the Six Flags board, all of them Snyder designees, the report said. They are film producer Harvey Weinstein, former congressman Jack Kemp and advertising executive Michael Kassan. The board representation followed a successful proxy solicitation by Snyder's Red Zone investment group. "This appointment follows the mutual decision of the board of directors and Kieran Burke to terminate the employment of Mr. Burke as chief executive officer, president and chief operating officer," Six Flags said. Snyder's group reported a roughly 11% stake in the company in its most recent filing with the Securities and Exchange Commission. Six Flags' shares have enjoyed a resurgence since Snyder and other disgruntled investors announced their proxy battle last summer. The stock was trading around $4 as recently as mid-July and closed Tuesday at $7.15. "With the sale process over, Mark Shapiro will focus on implementing new operational strategies that will help to maximize stockholder value in the long term," Six Flags said. "We recognize the company's significant debt load and the effect that such debt has on any transaction involving the company. We are committed to bringing the debt load to a more appropriate level." Get Jim Cramer's picks for 2006.