Viagogo bought rival StubHub in February 2020 for $4.1bn (£3.1bn). But the CMA says the merger lead to a “substantial reduction in competition in the secondary ticketing market in the UK”.

It says this could lead to customers who use secondary ticketing platforms facing higher fees or poorer service.

StubHub’s ticketing business operates in a number of territories including North America, the UK and several countries in Europe, and South America and Asia. In the UK, Viagogo and StubHub are the two main providers of secondary ticketing platforms.

Selling Stubhub’s international business means it will be independently owned and run by a separate company, with no input from Viagogo.

The CMA will determine key conditions of the sale, such as the right of the purchaser to use the StubHub brand for the next 10 years. The regulator will also need to approve the purchaser of the business before any sale.

The CMA considered evidence from customers, competitors and other stakeholders, including consumer groups.

It found that Viagogo and StubHub compete closely against each other in the UK’s secondary ticketing market and have no significant competitors. Together, they have a combined market share of more than 90%.

It found that other distribution channels, such as capped-price ticket exchanges, classified ad sites, social media and the primary ticketing market itself, would not be able to stop the merged business from pushing up fees or reducing quality of service.

Stuart McIntosh, chair of the CMA inquiry group, said: “The CMA has focused on ensuring competition in this sector works best for UK consumers. After examining all the options, including unwinding the merger in full, the evidence shows that Viagogo selling StubHub’s international business will resolve our competition concerns, effectively and proportionately.

“Creating a fully independent StubHub international business will maintain competition in the UK and help ensure that the users of these ticketing platforms don’t face higher prices or poorer quality of service.”

Adam French, Which? consumer rights expert, said: “It’s right that the CMA has taken action as the merger between two of the biggest players in the secondary ticketing market could result in higher fees or worse service for consumers.

“Which? has previously found evidence of Viagogo ripping off customers and treating them poorly, and there remains a lot to be done before the secondary ticketing market works effectively for consumers.”