PepsiCo Inc

said it was taking the essential step of changing its global structure by creating the new job of president to integrate its sprawling operations worldwide, and was bringing back a former executive to head its food and snacks business in the Americas.

PepsiCo Chief Executive Indra Nooyi, who has come under pressure from Wall Street for a stagnant stock price and a lagging North American beverage business, in a statement on Monday said the moves were needed to help PepsiCo keep growing.

Nooyi's five-year tenure has been hurt by the global financial crisis, recession and unprecedented commodity inflation. She has been criticized for taking her eye off the core business of sodas to expand into healthier products such as hummus and drinkable oatmeal.

The changes announced on Monday will deepen PepsiCo's management bench.

PepsiCo tapped an alum, Brian Cornell, who most recently was CEO of Sam's Club, part of Wal-Mart Stores Inc , to become CEO of PepsiCo Americas Foods. He will be responsible for Frito-Lay North America, Quaker oatmeal and other brands.

Cornell, who headed Sam's Club for nearly three years until he left last month, previously held senior roles at the Michaels arts and crafts specialty retailer, where he led a turnaround, and was chief marketing officer for supermarket chain Safeway .

Prior to that, Cornell worked at PepsiCo in a number of positions, including president of Tropicana and of PepsiCo North America Foodservice. He will report to Nooyi, who praised him for having what it takes to be a senior executive of a large public company.

Cornell replaces John Compton, who will take up the newly created job of president of PepsiCo and oversee global operations and look for ways to reduce PepsiCo's costs. Compton has worked at PepsiCo for 28 years.

Its shares were up 45 cents, or 0.7 percent, at $63.60 in premarket trading.

(Reporting By Phil Wahba in New York. Additional reporting by Mihir Dalal in Bangalore; Editing by Maureen Bavdek)