France began choosing a new president Sunday after a frenzied campaign among a dozen contenders in a vote with unpredictable results. Only four of the candidates, including conservative front-runner Nicolas Sarkozy and Socialist Segolene Royal, placing No. 2 in polls, had a real chance of being among the top two scorers who will face each other in a final round of voting May 6, the Associated Press reported. The new president replaces Jacques Chirac, ending 12 years as head of state at the close of his second mandate. For the first time, voting was staggered, with France's overseas territories going to polls on Saturday so that the votes of French in the country's far-flung regions would be sure to be counted. First estimates of all results were expected at 8 p.m. (1800GMT). When polling stations threw open their doors in mainland France at 8 a.m. (0600GMT), no one could say with certainty whether the nation's 44.5 million potential voters would give Sarkozy and Royal the top two spots, the Associated Press reported.