WASHINGTON (AP) -- The Justice Department says it will investigate the proposed merger of ticketing giant Ticketmaster Entertainment Inc. with Live Nation Inc.

Department spokeswoman Gina Talamona said Wednesday the department will vigorously enforce antitrust laws and therefore thoroughly investigate the proposed deal.

Some lawmakers are already calling on the government to reject the deal.

The deal would match the world's dominant ticket seller, Ticketmaster, with Live Nation, which was once it's biggest client and is the world's No. 1 concert promoter.

A Justice Department investigation could take months or longer, and the department has probed Ticketmaster in the past.