ROME, Dec 19 - Italian industrial orders, a gauge of future production, were unchanged in October from September in adjusted month-on-month terms, national statistics agency Istat said on Wednesday. Year-on-year, orders dipped an unadjusted 0.2 percent, with national demand up 0.7 percent and international demand sliding 2.1 percent. Istat also said industry sales fell an adjusted 2.0 percent month-on-month in October and climbed an unadjusted 0.6 percent. The statistical series is considered extremely volatile.//