The U.S. Department of Justice is preparing to file an antitrust lawsuit against Live Nation as soon as next month, the Wall Street Journal reported on Monday, citing people familiar with the matter.

Live Nation's subsidiary Ticketmaster, which for decades has been condemned for hardball tactics and high prices, was also widely criticized in 2022 after botched ticket sales for Taylor Swift's "Eras" tour, feeding demands that the two companies be investigated for harming consumers.

The lawsuit would allege that Live Nation had leveraged its dominance in a way that undermined competition for ticketing live events, the WSJ report said.

The U.S. DOJ and Live Nation did not respond to Reuters' request for comment.

Shares of the Ticketmaster-parent dropped about six per cent in extended trading.

Last year, Live Nation was issued a subpoena by a U.S. Senate panel for documents pertaining to ticket pricing, fees and secondary sales.