By Aditi Shrivastava and Phil Wahba
(Reuters) - Wal-Mart Stores Inc
McMillon, a 47-year-old Wal-Mart veteran, will take charge after the holiday shopping season at a time when the company is facing intense competition from dollar stores and other discounters, such as Target Corp
"McMillon was responsible for the growth area for Wal-Mart - international sales - and that's why he got the nod," said Walter Loeb, president of retail consultancy Loeb Associates.
Wal-Mart, whose shares rose 0.5 percent in early trading, has missed Wall Street estimates for U.S. comparable sales for three quarters in a row.
McMillon, currently CEO of Wal-Mart's second-largest operating unit, will start in his new role on February 1, the company said in a statement on Monday.
Originally from Jonesboro, Arkansas, McMillon joined Wal-Mart in 1984 as a summer employee in a distribution center. After studying for an MBA degree, he rejoined the company in a Tulsa, Oklahoma store in 1990.
He was promoted to his current role as head of Walmart International in January 2009. Prior to that, he was president and CEO of the company's retail warehouse chain, Sam's Club.
"McMillon has done just about every job there is (at Wal-Mart)," said Joe Feldman, analyst with Telsey Advisory Group.
"He's a good fit culturally and, as a young 47-year-old, there's an opportunity to be there for a long time," he said.
Duke, 63, will continue as chairman of the executive committee of the board and stay on as an adviser to McMillon for a year.
During his five-year tenure as chief executive, Wal-Mart's share price has risen by just over half, underperforming a more-than doubling of the S&P 500.
Duke's salary for the fiscal year ended January 31, was $1.3 million, while his total remuneration was $20.7 million, according to a regulatory filing in April. McMillon's total compensation for the period was $9.6 million.
Wal-Mart did not give details of his future salary as CEO.
Wal-Mart shares were up 0.49 percent at $80.20 in early trading on the New York Stock Exchange.
(Writing by Robin Paxton; Editing by Joyjeet Das and Ted Kerr)