Third quarter revenue slipped for British telecommunications firm Vodafone Group Plc compared to the same period of its previous financial year. For the three-month period, Vodafone posted total revenue of €11.372 billion ($12.25 billion), less than the €11.638 billion registered for the same period last year. Service revenue stood at €9.383 billion as against the previous year’s €9.52 billion. Other revenue slipped to €1.989 billion from €2.118 billion a year ago. Excluding items, looking ahead, for the full year, Vodafone still expects to report earnings before interest, taxes, depreciation …