China's e-commerce giant Alibaba is launching its mobile payment service Alipay in Europe.

Chinese customers will be able to use Alipay in the U.K., Germany, France and Italy this summer.

The move marks Alipay's biggest expansion out of Asia so far.

Alipay will be launched largely in partnership with Wirecard, a large European processor.

Once available in Europe, users can pay by presenting a barcode in the Alipay Wallet app that the merchant can scan with a handheld scanner.

Alipay is forecast to gain popularity in Europe thanks to its potential for increased purchasing from Chinese tourists.

Data from the World Travel & Tourism Council shows Chinese tourists spent 215 billion U.S. dollars abroad last year, up 53 percent from 2014.

Alibaba said Alipay was used by 120 million users abroad last year.

The service now processes 170 million transactions per day worldwide.