* Deal expected to close in Q3 (Adds further details on deal, background): ZURICH (Reuters) - A consortium led by Swiss asset manager Partners Group Holding (PGHN.S) will buy Techem from Macquarie (MQG.AX) in a deal that values the German metering company at an enterprise value of 4.6 billion euros ($5.4 billion), Partners Group said on Friday. The buyers include Caisse de dépôt et placement du Québec (CDPQ) and Ontario Teachers’ Pension Plan as well as Techem’s management team, it said in a statement.