Chinese advertising firm Focus Media (NSDQ: FMCN) is exploring a spin-off of its fast growing mobile and internet advertising units, according to TheStreet.com, citing people familiar with the company’s plans. The company’s primary business is out-of-home advertising (outdoor, elevators, etc.), but it’s been expanding in the wireless and internet arenas through acquisitions—last year, buying Chinese mobile ad firm Dotad for $30 million, and earlier this year, acquiring online ad firm Allyes for $100 million. These areas are now a sizable part of Focus Media’s business: In its latest quarter, the company did $151.4 million in total revenue, with mobile accounting for $14 million and internet ads contributing $42.5 million, totaling 37.4 percent of revenue. So far there’s nothing official from the company, although on its latest conference call, CEO Jason Jiang acknowledged that such a move was under consideration (transcript).

Still, the company is bullish on its core business. It recently acquired CGEN Digital Media, which runs a network of in-store digital ads, for $168.4 million, with $181.6 million in possible additional payments (release). Shares of Focus Media ended up over 2 percent today.

• Focus Media to Acquire Chinese Online Ad Firm Allyes for $300 Million
• Focus Media to Acquire Chinese Mobile Ad Firm Dotad For $30 Million