Chinese firm Jingtian & Gongcheng is ending its three-year-old association with Mayer Brown JSM and launching its own Hong Kong law practice.

The Beijing-based firm said in a statement that it decided to launch its own Hong Kong law practice this August to "further strengthen its competitive advantage in overseas capital markets".

However, both firms said they would continue to work together in joint business development initiatives and cross-border matters under what they described as "a global cooperation agreement".

Jingtian first entered Hong Kong in 2015 via a formal association with Mayer Brown JSM. Under Hong Kong law, non-local firms are required to form associations with Hong Kong firms for three years before offering local law advice on their own.

The Chinese firm's choice of partner firm was unconventional, however. Mayer Brown JSM, as the firm is known in Asia, is the result of a 2008 merger between the US firm and Johnson Stokes & Master, which was then one of the two largest law firms in Hong Kong. It now has about 200 lawyers in Hong Kong.

The association has seen the firms share office space, collaborate in business development and work together on client matters.

Most of Jingtian's peers, such as FangdaHaiwen and Han Kun, opened in Hong Kong by setting up their own affiliated Hong Kong firms. Others, such as Zhong Lun, entered an association with an existing boutique in the hope of a full merger after three years.

Jingtian is one of the top Chinese firms that handle Hong Kong listing work. Earlier this week, it served as the underwriters' Chinese counsel on Xiaomi's $4.7bn initial public offering on the Hong Kong Stock Exchange – the bourse's first listing under a dual-class share structure. The Xiaomi deal was enabled by a listing rules change implemented by the stock exchange in April. As a result, more Chinese companies are expected to list in Hong Kong this year.

According to the latest China 40 survey, 382-lawyer Jingtian reported $74m in gross revenue in 2016.