By Simon Jessop and Elizabeth Howcroft LONDON (Reuters) -Asset manager Allianz Global Investors, part of German insurer Allianz, said on Wednesday it had set up a new unit focused on ‘impact’ investing in private markets, as part of a sustainable investing drive. AllianzGI, which manages around 647 billion euros ($730.27 billion) in assets, will look to invest in private companies helping solve environmental or social issues in a measurable way, it said in a statement. Interest in companies performing better on such measures has surged in recent years as more investors expect such investments …