candidate: The deal is later shelved , owing to shareholder unrest 2012 Ontario Teachers ' Pension Plan ( Teachers ' ) and KIRKBI Invest A / S make EUR 500 million investment in ISS 2013 ISS is named world ’s best outsourcing company as the International Association of Outsourcing Professionals ranks ISS as the # 1 on its annual list of the world ’s best outsourcing service providers – The Global Outsourcing 100 2014 ISS lists on the OMX Nasdaq Copenhagen Stock Exchange in Denmark ’s biggest IPO in two decades