China's largest brokerage is expanding its global footprint. Citic Securities has bought a stake in US brokerage firm BTIG, the company's latest move to grow outside of China through buying a holding in a Western investment firm.

Citic made the purchase through its Hong Kong-based brokerage CLSA Asia-Pacific Markets, which it bought from French bank Crédit Agricole for $1.25 billion in 2013. That deal was the first major acquisition by a Chinese broker of a foreign competitor.