Under the deal, Aspire Global will provide its full proprietary offering including player account management (PAM), casino games and sports betting through its BtoBet sportsbook.
Aspire Global said that it would consult with WIN Group throughout the migration process to ensure there is no downtime for customers.
Aside from Winners.bet, WIN Group is also the company behind the Win.gg esports media website.
“As a market leader, we know that people betting on esports have high expectations for the user experience and our research indicates that the platforms currently in the market haven’t matched their expectations,” WIN Group chief executive Stephen Shoemaker said.
“Our new 2022 platform will change this by bringing an online wagering platform built for the esports enthusiast.”
Aspire Global chief executive Tsachi Maimon added: “Esports is one of the most exciting segments in igaming and we are determined to lead the development in this important area.”
The agreement comes after Aspire Global last week posted €213.3m (£178.1m/$242.8m) in revenue for 2021, representing a 31.8% increase on the previous year.
Those results follow online lottery platform provider NeoGames submitting an SEK4.3bn offer to acquire 100% of Aspire Global’s shares.