Six Flags, whose empire of amusement parks includes Enchanted Village and Wild Waves in Federal Way, is no longer for sale.

The company put itself on the auction block in August, but the company announced Dec. 14 that no formal bids were received and the process for a potential sale has ended. A shakeup of the top management of Six Flags, stemming from an attempted takeover last summer, also was announced.

The company plans to “richly enhance each park’s environment” to create an “enjoyable” family atmosphere, said Mark Quenzel, a new vice president of parks strategy and management.

In addition to Quenzel, Six Flags appointed Mark Shapiro, who formerly worked in cable television, as chief executive officer. He replaces Kieran Burke, who left the top position in a mutual decision with the board of directors.

Daniel Snyder, whose investment firm, called Red Zone, tried to seize control of Six Flags earlier this year, is the new chairman of Six Flags’ board.

Snyder, who expressed displeasure with Six Flags’ performance for more than a year after buying an interest in the company, had proposed boosting Red Zones’ stake to 35 percent, becoming Six Flags’ chairman and making Shapiro the CEO.

Shapiro resigned as CEO of Red Zone upon taking the reins of Six Flags. He also was a programming executive for the ESPN cable television sports channel until October.

Quenzel, too, is a former ESPN executive. He helped create X Games, a youth-oriented sports franchise featuring competitions such as skateboarding.

Other revamping of Six Flags’ hierarchy includes three additions to the board: Jack Kemp, a former congressman who was the Republican candidate for vice president in 1996; Harvey Weinstein, founder of Miramax Films; and Michael Kassan, a brand development consultant.

The board in August called for offers from possible buyers of Six Flags. The auction process was is in response to the takeover actions of Red Zone and Snyder. The board, saying it wanted to ensure maximum value for stockholders in any possible sale of Six Flags, unanimously opposed Red Zone’s attempt to gain control of the company but said Red Zone could be a bidder.

In addition to Enchanted Village-Wild Waves, Six Flags operates 27 theme parks in 15 states in the U.S., one in Canada and one in Mexico. Six Flags also runs a hotel and a 2,000-site campground at its park near Buffalo, N.Y.

The corporate headquarters are in Oklahama City, Okla.

Several parks opened highly publicized new rides in 2005, including Zooma Falls at Wild Waves.

The company bought the Federal Way operation in 2000 and since then has added 12 rides to the 70-acre complex.

In response to a question about whether Enchanted Village-Wild Waves or any other parks might be offered for sale individually, Debbie Nauser, a Six Flags vice president, said the Federal Way attraction “remains one of the (company’s) 30 great parks.”

According to published reports, Six Flags had $2.3 billion in long-term debt as recently as June 30. Snyder said “we are committed to bringing the debt load to a more appropriate level” in order to reduce its effect “on any transaction involving the company.

Snyder owns the Washington Redskins professional football team.