Clear Channel Outdoor Holdings Inc., the wholly owned billboard advertising subsidiary of Clear Channel Communications Inc. (CCU), may raise up to $350 million in an initial public offering (search), according to a regulatory filing on Wednesday.

The San Antonio, Texas-based company did not set terms for the expected offering nor did it name expected underwriters. The company plans to use the proceeds to repay existing debt, according to the filing with the Securities and Exchange Commission (search). .

The company earned $11.6 million on revenue of $1.26 billion in the first six months of 2005 after earning $2.9 million on revenue of $1.16 billion in the first half of 2004, the prospectus said.

Competitor Lamar Advertising Co. (LAMR) earned $12.8 million on revenue of $883.5 million for the full year 2004. Its stock currently trades at $42.74 a share, or about 92 times expected 2005 earnings, according to Reuters Estimates.