Mapletree Investments said it has pre-leased 40 per cent of the office space at its Mapletree Business City. Mapletree said it's talking to more potential clients who may take up another 15 per cent of space before the project is completed mid next year. Topping out the Mapletree Business City, the company already has another reason to celebrate. Fourth-tenths of some 1.7 million square feet of office...