Watterson is currently owned by its chief executive David Tsang, who has agreed to sell the entire issued share capital to the Evolution subsidiary, Evolution Securities China (ESCL), for an undisclosed amount.
The deal marks an expansion in Evolution's Chinese investment unit, reflecting their increased interest in the emerging market.
ESCL already has specialist research activities in Shanghai, and hope that the acquisition of Watterson will provide the company with full access to the Hong Kong equity markets.
Watterson is already licensed by the Securities and Futures Commission of Hong Kong to conduct corporate finance and securities dealings activities in the region, and has led fundraising for a number of Hong Kong market-listed companies.
It currently has gross assets of around Â£900,000.
The deal will have to meet with the approval of the Hong Kong regulators, which is expected at the end of May.
The Evolution Group is a UK-based financial services group which acts as a holding company for financial services companies, dealing in securities, investment banking and fund management.