New York City ? Theme-park operator Six Flags Inc., which has been struggling with falling attendance and a large debt load, said Thursday it will sell seven of its 30 North American parks for $312 million.

The sale comes after a management shakeup at Six Flags in recent years. Mark Shapiro, a former executive at ESPN, became chief executive of the company in December 2005 following a proxy fight led by investor and Washington Redskins owner Daniel Snyder that resulted in the ouster of former CEO Keirian Burke and other executives.

The parks are being bought by Jacksonville, Fla.-based park operator PARC 7F-Operations Corp.

The seven parks are Six Flags Darien Lake near Buffalo, N.Y.; Six Flags Elitch Gardens in Denver; Frontier City and the White Water Bay water park in Oklahoma City; SplashTown in Houston; Waterworld USA in Concord, Calif.; and Wild Waves and Enchanted Village in Seattle.