Live Nation Entertainment, the concert and ticketing giant, is in advanced talks to buy a majority stake in C3 Presents, the country’s largest independent promoter, whose portfolio includes the popular Lollapalooza and Austin City Limits festivals.

The prospective deal, in negotiations for months but still not completed, would give Live Nation a stake of 51 percent in C3 Presents and value C3 at around $250 million, according to two people with knowledge of the talks.

Representatives of both companies declined to comment.

C3, based in Austin, Tex., is run by three friends all named Charles or Charlie — in the music industry, they are widely known as “the Charlies” — and has grown quickly from its founding in 2007.

Last year, it sold 2,025,002 tickets to its events, according to the concert industry trade publication Pollstar, with gross sales of at least $124 million, according Billboard. The company, which also controls concert venues in Austin and books performances at casinos around the country, is said to have earnings of about $20 million a year.