(Yicai) Aug. 21 -- JD.Com's stock plunged after US retail giant Walmart sold all of its shares in the Chinese e-commerce giant for around USD3.6 billion.

JD.Com [HKG: 9618] closed 8.7 percent lower at HKD102.40 (USD13.14) a share in Hong Kong today, after earlier sinking by as much as 12 percent. Its New York-listed stock [NASDAQ: JD] fell 4.6 percent to USD28.19 yesterday.

Walmart no longer holds any JD.Com shares, according to an announcement released by the US Securities and Exchange Commission yesterday.

Arkansas-based Walmart was JD.Com's second-largest shareholder with a 9.4 percent stake as of March 31, just behind Chairman Liu Qiangdong, who held 11.2 percent, the Beijing-based firm’s latest financial report showed.

Walmart sold its 144.5 million JD.Com shares at USD24.95 each yesterday, Bloomberg News reported today, adding that the US retail giant plans to use the proceeds to raise investment in its other businesses in China, such as the rapidly developing membership-only warehouse retail chain Sam's Club.

JD.Com bought back shares about USD390 million of its own stock today, completing a USD3 billion share repurchase plan announced in March, the company said.

Walmart and JD.Com allied in 2016 when the US retailer transferred its stake in Chinese e-commerce platform Yihaodian to JD.Com in exchange for about 5 percent of its stock. Walmart raised its stake several times thereafter, once exceeding 10 percent.

The pair have also developed a series of business tie-ups. Walmart's retail stores use JD.Com's logistics and e-commerce systems for instant delivery services in China, while JD.Com enriched its product categories through the other's global sourcing and supply chain systems.

After years of cooperation, Sam's Club and Walmart's e-commerce businesses in China have developed well, so the company has chosen to recoup its investment to alleviate its own financial pressures, a person familiar with the matter told Yicai.

Walmart's net profit tumbled 43 percent to USD4.5 billion in the three months ended July 31 from a year earlier, while revenue rose 5 percent to USD169.3 billion, according to its most recent earnings report.

JD.Com's second-quarter net profit surged 92 percent to USD1.7 billion, maintaining strong growth despite fierce competition in China. Revenue rose 1 percent to USD40.1 billion.

Editors: Dou Shicong, Martin Kadiev