Alibaba Group Holding Ltd. agreed to merge its South Korean operations with E-Mart Inc.’s e-commerce platform to better compete in the country’s fast-paced online retail sector.AliExpress International and Gmarket are creating a 50-50 joint venture, according to a stock exchange filingBloomberg Terminal by E-Mart which confirmed a report by Bloomberg News. The companies plan to make further investments in the JV, which will own 100% of Gmarket....