It’s no secret that the special servicing business is booming. The amount of CMBS loans in such care—penciling in at $43 billion at the end of January—has doubled in the past year alone, according to Fitch Ratings. Special servicing, which generates management and resolution fees, can be quite a lucrative business. And that fact was probably not lost on locally based Island Capital Group, which picked up Centerline Capital Group’s special servicing arm yesterday. The deal represents the second such buy in the past year, and industry observers suspect it will not be the last.