West Ham have announced the renewal of their agreement with Betway, which is "the largest partnership deal" in the club's history.
Online gambling firm Betway has been the club's shirt sponsor since February 2015, and a year later signed an extension through to May 2020, which was reportedly worth more than £10million per season.
West Ham vice-chairman Karren Brady said this new "long-term" deal with Betway was a signal of the club's intention to continue to move forwards.
"After working together successfully for four years, this is a new, long-term, record-breaking commercial deal for the club, which shows the faith that Betway has in West Ham United and our iconic global identity which has seen us recognised as one of the world's biggest football brands," Brady said.
"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."