The boards of Ticketmaster Entertainment Inc TKTM.O and Live Nation Inc (LYV.N) approved an agreement to merge, the Wall Street Journal said.
Ticketmaster's board approved the deal on Sunday, but a handful of unresolved issues prevented Live Nation from doing so for around 24 hours, the newspaper said.
The Live Nation board reconvened Monday afternoon and the deal won approval, the paper added.
The paper cited people familiar with the matter as describing the sticking points as relatively minor, including accounting issues.
The agreement to merge lays the groundwork for what could be an intense regulatory review and, ultimately, the creation of an entertainment powerhouse of game-changing proportions, the newspaper said.
The two companies have different core businesses but have been moving into each other's territory.
The new company would integrate Ticketmaster's dominant operation for selling seats at music, sports and theater events; its sizable artist-management division, Front Line; and Live Nation's extensive network of large and small concert venues, regional concert promoters and a number of related businesses like T-shirt makers and fan-club operators, the paper said.
Ticketmaster and Live Nation could not be immediately reached for comment by Reuters.
(Reporting by Bhaswati Mukhopadhyay in Bangalore)