The Deerfield, Ill., didn't disclose the terms, but Sky News pegged the value at about £200 million ($277.22 million).
Grenade, Solihull, U.K., is well known for its protein bars. Its Carb Killa line has been a top seller since 2016, Mondelez said in a statement. The brand has expanded into other performance-nutrition products, including shakes, spreads and cookies.
Top markets for Grenade include Europe, North America, and the Asia Pacific, with the brand seeing increased demand amid the pandemic. Europe saw a 6% revenue increase last quarter, while revenue in North America increased 14%, Reuters reported.
Grenade was founded in 2010 by Alan and Juliet Barratt. Alan Barratt, who is chief executive, said in a statement that the partnership with Mondelēz "gives us access to enormous [resources]."
Barratt will maintain a minority interest in the company and Grenade will operate independently, Mondelez said.
The deal is expected to close this month.
Mondelz operates in more than 150 countries globally and posted revenue of $27 billion for 2020.
The company is known for its snack brands, including Oreo, belVita, and LU biscuits; Cadbury Dairy Milk, Milka, and Toblerone chocolate; Sour Patch Kids candy, and Trident gum.
At last check Mondelēz shares were trading 1% higher at $58.68.