Activist investor Nelson Peltz sent a letter to PepsiCo this week saying that Peltz' firm, Trian Fund Management, views "structural change as the best path forward to generate sustainable increases in shareholder value." Trian says it would buy additional shares of a separate beverage business, and would be willing to join the board of such a company.

"Freed of allocated corporate costs and bureaucracy, and able to be nimble and lean, we believe a standalone beverage business will not only compete, but thrive," says the letter. Funds managed by Trian own about $1.2 billion of PepsiCo stock.