The Dublin office of KKR, the New York private equity and finance behemoth, stands sentinel on St Stephen’s Green in the heart of the city, a shimmering six-storey office block that was developed on a site once owned by the neighbouring Department of Justice. The building, which produces €6.5 million in annual rental income, also houses the stockbroking firm Cantor Fitzgerald, the global law firm Maples and the fund administrator HedgeServ. And from this marquee office block, KKR operates the corporate equivalent of a cash machine. The New York finance house operates a number of subsidiary businesses from Dublin, including…