Rome, October 18 - Italy's anti-trust authority is investigating concert ticket presale companies such as TicketOne SpA and four operators on the secondary ticket sales market, consumer groups said Tuesday. The probe will look into why it is virtually impossible to purchase tickets to see top bands such as Coldplay in Italy after presales are over and the tickets go on sale to the general public, the National Consumer Union and Altroconsumo groups said. TicketOne SpA holds exclusive rights to Internet sales for major national and international acts, and sells tickets at prices fixed by organizers on behalf of the artists. However, the tickets show up sometimes minutes later on secondary online sites at a huge mark-up, the anti-trust authority said. This happened for the Adele, Bruce Springsteen, Foo Fighters, David Gilmour, Red Hot Chili Peppers, and Renato Zero tours, it said. The agency said it is investigating whether there have been any breaches of the consumer code and whether TicketOne somehow allowed single buyers to instantaneously purchase massive amounts of tickets online.