Simpson Thacher & Bartlett and Sullivan & Cromwell are leading on ecommerce giant Alibaba Holdings Ltd.’s $4.6 billion investment in Chinese retailer Suning Commerce Group Ltd.

In a deal announced on Monday, Hangzhou-based Alibaba said it was buying a 19.9 percent stake in electronics store chain Suning. Meanwhile, Nanjing-based Suning will also buy $2.3 billion worth of Alibaba shares and hold a 1.1 percent stake in the New York Stock Exchange-listed company.