(Reuters) - China’s JD.Com said on Monday it would invest $800 million in on-demand delivery platform Dada Group, following which the e-commerce firm will own about 51% of Dada. The investment comes at a time when JD.com is spinning off its logistics business, the in-house delivery network that gave it competitive advantage over larger rival Alibaba Group. JD had merged its online-to-offline unit, JD Daojia, with Dada in 2016. Dada-JD Daojia, a Chinese online grocery and delivery firm, then in 2018 raised $500 million from Walmart Inc and JD. JD.com on Monday also agreed not to sell, transfer or dispose of any shares bought in the deal for six months after the closing. U.S.-listed shares of Dada jumped nearly 19%, while those of JD.com were up 0.5% in trading before the bell.