Martello, who joined Wal-Mart in 2005 as CFO of its international unit, helped lead the U.S. retailer's acquisition this year of a minority stake in Yihaodian, a Chinese online supermarket operator. Her replacement hasn't been named, Lorenzo Lopez, a Wal-Mart spokesman, told Bloomberg.

Martello is a U.S. citizen of Chinese and Philippine extraction. A CPA, she has an MBA from the University of Minnesota and earned a bachelors degree from the University of the Philippines. She has vast knowledge of the finance and control area and solid experience in the food and beverage business as well as the retail segment. Her work at Kraft was from 1985 to 1995, in finance and business administration. At Borden (1995-1998) she was controller.

From 1998-2005 she was CFO with NCH Marketing Services Inc., a former subsidiary of Nielsen, and then was COO, and late president USA. At Wal-Mart, since 2005 she has been steeped in retail and e-commerce at Wal-Mart, first as senior vice president, CFO & strategy, for Wal-Mart International, and then in her EVP, COO, global ecommerce and emerging markets role.

Besides her financial background, she is expert in consumer and branded goods category, Nestle said.

"I am confident that Wan Ling will blend well into the Nestle culture and that her strong experience in finance and the food and beverage business, both from the industry and retail angle, will allow her to further enhance the Nestle model combining top-line growth with continuous margin improvement and an improved return on invested capital," Nestle CEO Paul Bulcke said. "Jim Singh has strong human qualities and is a highly respected professional. Since I became CEO I have been able to appreciate the full extent to which Jim has been instrumental in steering Nestlé through these last challenging years."