US retail giant Wal-Mart Stores has announced a realignment of responsibilities among several of its senior executives, including the promotion of Tom Coughlin to the position of executive vice president and vice chairman, Wal-Mart Stores (USA).

In this new role, Coughlin, 53, will continue to be responsible for the US retail operations of Wal-Mart discount stores, Supercenters and Sam’s Clubs, and also assumes responsibility for key support functions such as logistics, real estate development and global procurement. He also assumes responsibility for the company's online operation, Walmart.com.

Wal-Mart also announced that Mike Duke, 53, has been promoted to the position of executive vice president, and president and CEO of the Wal-Mart Stores Division. Previously serving as executive vice president of administration, Duke is now responsible for the operations and merchandising of the company's Wal-Mart discount stores, Supercenters and Neighborhood Markets in the US.

The company said the changes are effective immediately.