Wal-Mart Stores Inc has named the 20-year company veteran Judith Mckenna as the new chief operating officer in the latest round of senior management reshuffle in the US.

Mckenna will replace Gisel Ruiz in the new role. She will be responsible for daily operations of Wal-Mart’s 4,300 stores in the US and its 1.3 million employees.

In a statement, Wal-Mart said McKenna will continue to oversee growth of its small format stores and the integration of e-commerce and store operations.

Mckenna’s appointment is the second major executive departure at the peak of the crucial holiday season, with the chief merchandising officer Duncan McNaughton departing just two days before the Thanksgiving/Black Friday weekend.

McKenna previously oversaw strategy and development in Wal-Mart’s international division and was COO of Asda Stores.

The changes are effective immediately, Wal-Mart said.

There has been a major reshuffle in senior management in the US under the new CEO Greg Foran, where the retailer is struggling to gain foothold after a nearly two-year slump.

Foran who joined last August is revamping the American operations with a series of "urgent agenda items" that include better stocking of shelves and boosting its fresh food offerings, reports Reuters.

Gisel Ruiz will now be the executive vice president of the company’s international people division, where she will oversee human resources overseas.

Wal-Mart posted its first growth in same-store sales since 2012 in the quarter ended October 31.