Sky News reported that both the entities were in discussions for several months and the takeover can be completed in the following weeks.
The transaction, if successful, will be the most significant acquisition by a Chinese firm in the UK fintech sector.
The deal value was not ascertained, however, one of the people familiar with the matter told Sky News that it could be more than £550m ($700m).
WorldFirst provides foreign exchange and currency-hedging services to financial groups and individuals includes businesses, banks and asset managers globally.
Established in 2004 by Jonathan Quin and Nick Robinson, the company is said to have transferred more than £60bn for its clients till date.
World First has already received a licence to operate in China’s fintech sector.
Valued $150bn, Ant Financial is planning to go public soon. Alibaba has around 33% stake in Ant Financial.
