As Live Nation get sets to launch its ticketing business in January, its battle with rival Ticketmaster is already heating up, according to the N.Y. Post.

Shares in newly public Ticketmaster are off 39% since early September, when Live Nation announced it now controls the future ticketing business of venue operator SMG, one of their competitor’s biggest clients.

Last week, Live Nation signed up another Ticketmaster client to a five-year deal in Manhattan’s Roseland Ballroom.

The rivals are now dueling in foreign territory as they look internationally for growth.

Several North American venues, including Cablevision's Madison Square Garden and Radio City Music Hall, will continue to use Ticketmaster, even if Live Nation is producing the event.

Ticketmaster, formerly a unit of Barry Diller's IAC, but now independent, is looking towards global expansion to combat Live Nation's push into ticketing.

In many Euro markets, the tour promoter, rather than the venue, dictates the ticketing partner, an advantage for Live Nation, which specializes in worldwide concerts from the likes of U2, Madonna and the Rolling Stones.

The company also has a powerful new ticketing partner in the Germany company CTS Eventim.

The U.K., Europe's top market, will also be increasingly competitive, while much of Latin America and Asia remain up for grabs.

Ticketmaster handled tickets for the Olympic games in China over the summer, while Live Nation recently announced deals with promoters controlling the touring markets in Mexico and Brazil.