Based on the Revolution Money P2P payments platform Amex acquired in 2010, Serve was unveiled in March, enabling users to buy goods and make person-to-person transfers online and through mobile phones.
Having tied up to major US carrier partners in Verizon and Sprint, the card giant has now secured an operating agreement with Lianlian Group, which serves around 300 million mobile accounts in the potentially massive Chinese market.
Under the deal, Lianlian can now use Serve to help power its own planned digital wallet that will let consumers top up mobile phone minutes, pay bills and purchase products and services.
Amex says that, as well as benefiting consumers, the new wallet will help to build new business for local merchants - 300,000 of which already act as Lianlian agents across China - in the fastest growing consumer market in the world.
Meanwhile, Amex is investing $125 million in the overseas LianLian Play business, as well as opening an enterprise growth group office in Hangzhou, with a team providing technical and consulting support to Lianlian.
Dan Schulman, group president, enterprise growth, Amex, says: "Our partnership with Lianlian Group will allow a more flexible payment option for consumers in China. By leveraging Serve into its infrastructure, Lianlian Group will be well positioned to enable consumers to bridge the gap between the limitation of paying with cash and the opportunities associated with digital commerce."