NEW YORK – Activist investor Marcato Capital Management has ratcheted up its attack against Buffalo Wild Wings Inc., seizing on the restaurant chain's weak earnings as further evidence to support the fund's goal of overhauling its strategy and board.

Buffalo Wild Wings, based in Golden Valley, is failing to deliver on its promise of 20 percent profit margins, international expansion and technology upgrade, Marcato said in a 51-page slide presentation, headlined "over-promising and under-delivering," that was released Wednesday.

Marcato launched a proxy fight against the company earlier this month, nominating four directors for its nine-member board on Feb. 6. The next day, the company reported disappointing earnings.

"Rather than articulating any real plan to address the weakness, they instead put forth rosy views that they plan to fix everything, but with no timeline, no numbers," Marcato founder and Chief Executive Mick McGuire said.

The activist investor and the company have clashed since Marcato disclosed its stake of more than 5 percent last July.

Buffalo Wild Wings' stock slid to $156.05 on Wednesday. It had reached a high of $190 two years ago.

One of Marcato's original critiques was that Buffalo Wild Wings did not franchise out enough restaurants, and the San Francisco-based fund is pushing for a 90 percent franchisee model. The franchisee vs. company-owned restaurant ratio is currently around 50-50, and the company has said the chain actively seeks out new franchisees.

In Marcato's slide presentation, it repeats its concerns about the board's lack of experience in the restaurant industry and casts doubt on Buffalo Wild Wings' ability to reach key targets. Marcato said the company has been unwilling to provide details on a timeline and how it would reach its stated promise of achieving 20 percent profit margins by 2018.

Morgan Stanley also cast doubt on that goal.

A Buffalo Wild Wings' spokesman said the company welcomed any input from shareholders and would respond to Marcato's presentation in due course.

Buffalo Wild Wings' annual meeting is expected in May.