(Adds details on small-format stores, e-commerce investment)
By Siddharth Cavale and Sruthi Ramakrishnan
June 6 (Reuters) - Wal-Mart Stores Inc appointed Gregory Penner as vice chairman, showing again that the world's largest retailer is looking at younger executives to revive its fortunes.
The appointment of 44-year-old Penner puts him in a position to succeed Chairman Rob Walton, his 69-year-old father-in-law.
Penner, who has been on Wal-Mart's board since 2008, is a general partner at Madrone Capital Partners, according to Wal-Mart's website. From 2002 to 2005, he was Wal-Mart's senior vice president and the chief financial officer of its Japan unit.
The announcement, made in Wal-Mart's annual shareholder meeting on Friday, comes at a time when the company's U.S. same-store sales are falling and it struggles to get beyond a bribery scandal at its Mexico unit that cost it more than $500 million since 2012.
Wal-Mart is also facing increasing dissent from its employees who, backed by unions, are demanding higher wages, better benefits and more full-time jobs.
The company appointed Doug McMillon, 47, as its chief executive in November to help stanch the fall in sales and improve its image following the Mexico scandal. He took the helm in February, replacing 64-year-old Mike Duke.
Wal-Mart said on Friday it was doubling down on small-format stores, typically one quarter the size of its supercenters, to broaden its customer base and fend off aggressive rivals.
The company, which operates nearly 350 smaller stores, said it would build 200 more Neighborhood Market stores and 80-100 Wal-Mart Express stores this fiscal year, Wal-Mart U.S. business head Bill Simon said in the shareholder meeting.
There have been concerns about how Wal-Mart is dealing with its core low-income customer base, which has struggled with a cut in food stamps and higher gas prices, and online competition from Amazon.com.
The company also said it would move fast on investing in technology to boost sales in e-commerce, its fastest growing business.
The move to appoint Penner as heir apparent highlights the Walton family's attempts to reinforce its control over the company founded by Rob Walton's father, Sam Walton.
The Walton family controlled 51 percent of Wal-Mart as of April 4.
The appointment aroused shareholder concerns about the company's indifference to growing criticism.
Some shareholders proposed the appointment of an independent chairman and sought disclosures on whether the company had recovered pay from executives involved in frauds.
They also sought transparency on whether the company was lobbying against a federal proposal to raise minimum wages.
These demands were voted down on Friday.
"There's no chance a (shareholder) proposal will be approved given the controlling stake of the Walton family," CtW Investment Group analyst Michael Pryce-Jones told Reuters.
Pryce-Jones, however, said Wal-Mart would find it difficult to ignore shareholder concerns as its performance suffers.
CtW Investment works with pension funds who own 4 million shares of Wal-Mart.
Wal-Mart's shares closed at $77.21 on the New York Stock Exchange on Friday. (Editing by Kirti Pandey and Don Sebastian)