TOKYO, Oct 1 (Reuters) - Japan's Mitsubishi Materials Corp plans to produce 166,848 tonnes of refined copper during October-March, it said on Monday, down 7.9 percent from the same period a year earlier. Following are details of the company's output plan, with comparisons against planned production in the first half of the financial 2018/19 year and actual production in the second half of 2017/18.