LONDON (Reuters) - American Express (>> American Express Company) has introduced instant blockchain-based payments using Ripple, a fintech start-up, for U.S. corporate customers sending funds to UK-based businesses that bank with Santander UK (>> Santana S.A.), the companies said on Thursday.

American Express said its FX International Payments (FXIP) business had partnered with Ripple to provide real-time, trackable non-card payments from the United States to Britain. Customers are already using the service, the companies said, and it would be extended in the future.

This marks one of the first major uses of blockchain, a shared database of transactions maintained by a network of computers on the internet that is best known as the system underpinning bitcoin.

Financial firms hope the nascent technology can reduce the cost and complexity of burdensome processes such as securities settlement and international payments, but many say widespread use of the technology is still several years away.

"American Express has a long history of integrating new technologies...,” said American Express's chief information officer Marc Gordon, in a statement.

"This collaboration with Ripple and Santander represents the next step forward on our blockchain journey, evolving the way we move money around the world."

San Francisco-based Ripple, whose main focus is blockchain-based cross-border payments, works with many big banks and is backed by firms including Standard Chartered Plc (>> Standard Chartered), Accenture Plc (ACN.N) and SBI Holdings.

The company is in a legal battle with rival blockchain startup R3 Holdco LLC over an options contract to purchase Ripple’s digital currency XRP. XRP has increased in value by more than 30 times as other cryptocurrencies have also soared.

"Transfers that used to take days will be completed in real time, allowing money to move as fast as business today," said Ripple CEO Brad Garlinghouse in a statement.

(This version of the story corrects 7th paragraph to show Ripple HQ is in San Francisco, not New York)

(Reporting by Jemima Kelly; editing by John Stonestreet)

By Jemima Kelly

Stocks treated in this article : American Express Company, Standard Chartered, Santana S.A.