Financial terms of the deal were not immediately available.
Searchlight also announced the appointment of Andy O'Brien as chief executive and Sam Florio as chief financial officer of the retailer.
O'Brien was most recently the chief executive of the Works Gourmet Burger Bistro chain, while Florio was formerly the vice-president of finance and business planning at Cara Operations Ltd.
M&M was founded in 1980 by Mac Voisin, who will remain an adviser to the company.
"Canadians love and trust M&M Meat Shops because they can count on the quality and convenience of its products. I am confident that the new team will continue to ensure that the brand remains a Canadian favourite," Voisin said.
M&M, based in Kitchener, Ont., has roughly 400 shops across Canada.