WASHINGTON (July 27, 2009)--A key senator is warning that the proposed merger of ticketing company Ticketmaster Entertainment Inc. and concert promoter Live Nation Inc. raises "serious competition concerns” and he’s urging the Justice Department to review the deal closely.

Sen. Herb Kohl, a Wisconsin Democrat, chairs the Senate Judiciary Committee's panel on antitrust issues.

In a letter Monday to Assistant Attorney General Christine Varney, he says the Justice Department should approve the transaction only if it will lead to cost savings that are likely to be passed along to consumers.

Ticketmaster and Live Nation have been seeking to allay antitrust concerns among lawmakers and regulators in Washington since they announced their proposed merger in February.