BlackRock has agreed to sell a 43-storey office building in Singapore to Qatar Investment Authority, a sovereign wealth fund, for S$3.4 billion, in what the US firm said was the largest-ever single-tower real estate deal in the Asia-Pacific region. Asia Square Tower 1, located along Marina View at Marina Bay, has more than 1.25 million square feet of net lettable area and has Citigroup as its anchor...