By Christine Murray and Elida Moreno PANAMA CITY (Reuters) – Panamanians vote for a new president on Sunday in the closest contest in a generation with opponents of President Ricardo Martinelli seeking to thwart the business tycoon’s attempt to maintain an indirect grip on power. Panama is a banking and trading hub and its successful canal has helped fuel the fastest economic growth in Latin America in recent years. Opinion polls show ruling Democratic Change (CD) party candidate Jose Domingo Arias, whose running mate is Martinelli’s wife, neck and neck with moderate leftist ex-Panama City mayor Juan Carlos Navarro of the Democratic Revolutionary Party (PRD). Just behind in third place is the Panamenista Party’s Juan Carlos Varela, the vice-president.
