American Express (AXP) and China’s largest Internet company, Tencent Holdings, are teaming to develop a way for customers to use Tencent’s online payments service to buy goods on web sites outside of China.

The move marks American Express’s first joint venture with a third-party online-payments provider in China, and it comes as the Chinese company continues to look for ways to expand its presence abroad.

Under the deal, users of Tencent’s Tenpay will be able to shop on certain key U.S. and British web sites. Payments will be made using an American Express online shopping service called “globaleshop.”

Financial details of the transaction were not disclosed. 

In a joint statement citing data from iResearch, the companies said total transaction volume processed by third party payment services in China grew 95% from the year-earlier period. 

Tenpay, which is a third-party, online payment platform and subsidiary of Tencent, currently has more than 20% share of that market in China with a customer base exceeding 150 million users, the companies said. 

"Our partnership with American Express will allow us to rapidly expand the scope of our business and accelerate our move into offering cross-border, online payment services," Tenpay general manager Luke Liu said in a statement. 

Earlier this year, the China Internet Network Information Center reported that the number of Chinese Internet users, already the world's largest, climbed 15.5% from a year ago to 485 million users.

The total number of online shoppers in China reached 173 million in June, according to that data.

Follow Jennifer Booton on Twitter at @Jbooton