The merger between Switzerland’s main ticket operators, Ticketcorner and Starticket, could be stalled or blocked altogether.

The country’s competition commission has decided to look into the case, as both companies would control some 90 percent of the Swiss market, Neue Zürcher Zeitung reports.

The commission said there were indicators that the merger could lead to a monopolistic position in the Swiss ticketing market. It will decide within four months whether to give the merger the go-ahead, impose conditions or halt it entirely.