Activist investor Marcato Capital Management on Tuesday warned Deckers Outdoor Corp. that it seeks to shake up management and the board by replacing all directors unless the footwear maker sells itself at an attractive price.

In a letter to the board, the San Francisco-based hedge fund said Deckers management has long ignored shareholders' suggestions to improve performance and worried that Deckers' current review to sell itself may not result in the best deal for shareholders.

Marcato owns nearly 6 percent of Deckers, the maker of UGG boots and apparel, and ranks as its fifth largest investor.

"Should Deckers’ strategic review process not culminate in a sale of the Company at an attractive value to all stockholders, we will be prepared to seek significant Board change at the Company’s next annual meeting by nominating a slate of director candidates to replace the entire Board," Marcato's portfolio manager, Mick McGuire, wrote to the board.

Deckers said in April that it was exploring a sale as part of a review of strategic options.

Fresh from winning board seats and ousting the long-serving chief executive officer at Buffalo Wild Wings Inc (BWLD.O) earlier this month, McGuire in a sharply worded letter laid out Deckers management's missteps and underscored the unhappiness of other large investors.

A least six shareholders have urged the company to sell itself, McGuire wrote, but noted that all suggestions for "corrective action" from shareholders have so far been "consistently ignored."

"The inevitable consequence has been a total collapse in shareholders’ confidence in the Company’s Board of Directors and management team," McGuire wrote.

Although Deckers has engaged an investment bank to explore a sale, the process has been too secretive for Marcato's taste. The fund manager also criticized the company's board, citing its lack of any big investors, lack of expertise in mergers and acquisitions and lack of "meaningful stockholder representation."

While the company has promised to cut $100 million in costs, McGuire said the savings should be at least twice that and said Marcato lacks confidence that current management and the board can get the job done.

Investment management firm Red Mountain Capital Partners LLC in March pushed Deckers for a sale, saying its stock had underperformed due to management's "consistently poor capital allocation decisions."

Deckers' shares were up 1.3 percent at $67.79 on Tuesday in afternoon trading and are up 22 percent since the start of the year.

Marcato's main investment fund has returned 8 percent through the middle of June while its smaller Encore International fund is up 18.3 percent.