Kraft Heinz is preparing to break itself up, a decade after an infamous merger of two of the biggest names in packaged foods that was orchestrated by Warren Buffett and Brazilian private-equity firm 3G Capital Partners.

A decade after the megamerger of Kraft and Heinz, the packaged food powerhouse is preparing to break up amid shifting consumer tastes and mounting financial pressure.

Kraft Heinz Co. is preparing to break itself up, people familiar with the matter said. Under the plan, the company could spin off a large part of its grocery business into a new entity, according to the people. This would allow it to focus on faster-growing segments such as sauces, they said.