Buffalo Wild Wings' CEO is leaving the struggling chain after activist investor triumphs in months-long battle for the board

Buffalo Wild Wings' CEO is leaving the company, following an activist investor's triumph in a months-long battle for the wings chain's board.

On Friday, Buffalo Wild Wings announced that Sally Smith would step down as CEO at the end of 2017, after more than 20 years at the company.

Less than an hour later, Marcato Capital Management announced that the company's shareholders had elected all three of the activist investor's nominees to the company's board - including Marcato's founder and managing partner Mick McGuire.

The end of Smith's leadership and the election of Marcato's nominees comes after months of disputes between the hedge fund and the restaurant company. McGuire, who has been called a Bill Ackman "protégé," kicked off the power struggle in August 2016, when he published an open letter accusing Buffalo Wild Wings' management of mismanaging the company.

The letter set off a brutal series of attacks and rebuttals between Buffalo Wild Wings and the activist investor, which now owns roughly 9.9% of the company's shares. Marcato accused Buffalo Wild Wings of ripping off franchisees; Buffalo Wild Wings said McGuire had a "track record of losses in the boardroom."

With Marcato's nominees elected to the board and Smith stepping down from her position, it looks like the hedge fund will be able to carry out its game plan at the chain, which would result in more locations owned and operated by franchisees.

"We are very pleased that our fellow Buffalo Wild Wings shareholders recognize that additional change on the Board is warranted to return Buffalo Wild Wings to a path of growth and long-term value creation, McGuire said in a statement. "We will bring the fresh perspectives, restaurant industry expertise and oversight the Buffalo Wild Wings Board needs to spearhead improvements at the Company."

In addition to McGuire, Buffalo Wild Wings shareholders nominated Pizza Hut CEO Scott Bergren and foodservice company CTI Foods CEO Sam Rovit to the board.

"I am proud of Buffalo Wild Wings' tremendous success. We have made great strides in executing our strategic plan and continuing to innovate to stay ahead of the competition," Smith said in a statement. "I am confident that the company, including its excellent management and Board, are solidly positioned for its next phase of growth and development."