By Elvira Pollina and Valentina Za MILAN (Reuters) – Telecom Italia (TIM) is expected to make a decision on a 10.8 billion euro ($12.2 billion) takeover proposal from U.S. private equity firm KKR by the middle of next month. The U.S. private equity fund made a non-binding approach to take the former phone monopoly private last November. It sought the backing of the company and the government, as well as a four-week due diligence process before it formalised a bid. But KKR has been forced to play a waiting game as Telecom Italia overhauled its management, ousting its fourth chief executive in s…