The online bookmaker and football club have been in partnership since 2015 and Karren Brady, West Ham United Vice Chairman, says the extension makes it a record-breaking commercial deal for the club.
Brady added: "We look forward to continuing to work with Betway as we embark on the next chapter for our great club, and we will use this partnership as a platform for success, both on and off the pitch."
This extension was confirmed despite ongoing pressure against advertising and sponsorship in sports betting in the UK.
The Industry Group for Responsible Gambling’s (IGRG) whistle-to-whistle ban on pre-watershed TV sports betting advertising was agreed in December and will come into effect in time for the start of the new Premier League season.
While that does not concern deals away from the TV screen, it has prompted analysts, operators and the new CEO at the Remote Gambling Association (RGA), West Himes, to say more needs to be done in regards to betting advertising.
Shortly after the whistle-to-whistle ban was announced, gambling PR consultant Alex Donohue said: "It's a case of out of sight, out of mind but, given the wider regulatory climate, the industry should prepare itself for similar scrutiny of marketing practices across all channels.
"If this was a bid to keep the wolves from the door, it could well end up being just the start of further wholesale changes."
GVC Holdings has also called for an end to sports betting advertising and is ending many of its football sponsorships.
