Transport for London (TfL) has announced a deal worth up to £15 million for its contactless ticketing system to be used around the world.
The agreement was reached with Cubic Transportation Systems (CTS), which provides smartcard technology to cities such as Sydney, Vancouver and Chicago.
Contactless payments by credit or debit cards were introduced on London's buses in December 2012 and expanded to cover Tube and rail services in September 2014.
Since then more than 500 million journeys have been made by more than 12 million unique credit and debit cards from 90 countries, as well as contactless-enabled mobile devices.
Selling TfL's knowledge in the UK and abroad was a key manifesto commitment of London Mayor Sadiq Khan.
Following the announcement of the deal with CTS, Mr Khan said: "I made a firm commitment to sell Transport for London's expertise around the globe. We will use the income from those deals for further investment in new infrastructure and to freeze TfL fares."
Shashi Verma, TfL's chief technology officer, said: "Contactless payments have completely transformed the way people pay for travel in London and this deal will allow other world cities to benefit from the hard work we put into making the system work for our customers."