Ant Financial, a financial services firm led by billionaire Jack Ma, has completed its acquisition of U.K.-based money transfer and currency exchange firm WorldFirst.

Ant Financial, a unit of Alibaba group and an affiliate of e-commerce giant Alibaba, has been in talks on to buy WorldFirst for $700 million in recent weeks.

WorldFirst recently announced plans to shut its U.S. operations to placate U.S. regulators, which previously rejected Ant Financial's prior bid to buy money transfer service MoneyGram for $1.2 billion. It rebranded the business under the name Omega, saying it would operate as an independent company.

Ant Financial declined to comment on the financial terms of the completed deal.

An Ant Financial spokesperson said WorldFirst was highly complimentary with its Alipay mobile payments service and the combination would help the companies better serve small businesses and promote financial inclusion around the world.

"The tie up will add WorldFirst's international online payments and virtual account products to Alipay's broad range of technology solutions, enabling us to reach a greater number of customers, especially in the fast growing area of cross-border e-commerce," the spokesman said in an email.

He confirmed Jonathan Quin would continue to lead WorldFirst and said the companies would work together to boost sustainable development by supporting SME's globally, including in the U.S. Quin reportedly sent a memo to clients confirming the deal.