A M Naik, Chairman and Managing Director of Larsen & Toubro, knows well that his core business of engineering and construction will be a big money spinner in the coming years. This is why he wants L&T to exit ancillary businesses of medical equipments and plastics machinery and pump in more money into these workshops. L&T has put its Rs 130 crore medical equipments business on the block and is talking to Siemens and GE to offload its holding.