Alibaba Group Holding Ltd has teamed with its largest shareholder SoftBank Group Corp to form a cloud computing service venture targeting Japanese customers, as the Chinese e-commerce giant expands one of its fastest growing businesses.

The venture known as SB Cloud Corp will open a new data center in Japan to tap SoftBank's customers ranging from startups to global organizations, extending a battle for customers with Amazon.com Inc.

Alibaba will provide services including data storage and processing services, the companies said in a joint statement. Alibaba's cloud unit almost tripled revenue to more than 1 billion yuan ($153 million) in the March quarter. The business could account for more than $1 billion of Alibaba's revenue by 2018 and the public cloud presents a $120 billion global market opportunity, according to research by SunTrust Robinson Humphrey Inc.

SoftBank, owner of Japan's third-largest phone business, will have a 60 percent stake in the new venture while Alibaba will hold the rest.

Alibaba's Japan venture follows last month's announcement of a partnership with one of South Korea's largest conglomerates SK Holdings Co.

China's biggest e-commerce operator earlier teamed up with Accenture Plc to target clients in China and Southeast Asia, and it said in April it would work with Germany's SAP SE.