The change will take place after Wal-Mart's annual shareholders' meeting on June 3, it said in a statement.

The revamp includes the retirement of Jim Walton, 67, the youngest son of late Wal-Mart founder Sam Walton, after 11 years on the board, the retailer said. His son Steuart, 34, has been nominated for a board seat.

Also departing are Aida Alvarez, a former member of U.S. President Bill Clinton's cabinet, retail industry veteran Roger Corbett, and Mike Duke, who was Wal-Mart's chief executive from 2009 to 2014.

Wal-Mart, which posted a double-digit profit decline last year as the dollar appreciated and costs rose as it hiked entry-level wages, said a smaller board would lead to better and faster decision-making.

The average board size for companies in the Standard & Poor's 500 index was 10.8 last year, according to the Spencer Stuart board index.

"The changes we are making are designed to maximize our effectiveness as we adapt to ever-evolving customer requirements," James Cash, lead independent director, said in the statement.

Both Alvarez, 66, a member of the auditing committee, and Corbett, 73, the former CEO of Australian retailer Woolworths Ltd, had been on the board for a decade, the normal tenure for independent directors, Wal-Mart said.

Duke's departure two years after leaving the CEO post is also in line with historical standards, it said.

Wal-Mart also said Wednesday that current CEO Doug McMillon's total compensation, including cash and stock, was valued at $19.8 million in the year ending Jan. 31, up from $19.4 million in 2014.

Last year, Wal-Mart's operating income fell 11 percent to $24.1 billion and sales dropped 0.7 percent to $482 billion, reflecting a $1 billion outlay to raise wages and the firmer dollar, which cut the value of overseas sales.

Excluding currency impacts, Wal-Mart's sales rose 2.8 percent to $499.4 billion.

Its core U.S. operations have shown some improvement, with sales at existing stores rising 1 percent last year, excluding fuel. Greg Foran, head of the U.S. business, saw his compensation fall to $11.5 million from $19.5 million, as his stock awards were lower after a big allocation last year due to his promotion.

(Reporting by Nathan Layne in Chicago; Editing by Richard Chang, Bernard Orr)

By Nathan Layne