Financial media magnate Michael Bloomberg, the unlikely new 'Hizzoner' of the Big Apple, who is scheduled to move into Gracie Mansion in the New Year, is not known for his political expertise. And even a pro-business journalist in the US opined that Bloomberg knows less about

New York than any mayor of the last 100 years.But the enterprising Bloomberg has already taken the first step toward meeting one of his biggest challenges head on - to rub along with the hugely powerful New York police, firefighter and teachers' unions. Last week, he visited with municipal union heads, impressing them with his eagerness to maintain a 'dialogue' in contrast to their generally acrimonious relationship with outgoing mayor, Rudolph Giuliani.