PARIS, April 22 (Xinhua) -- French voters were flocking en masse Sunday to cast their ballots in the first round of France's presidential election as officials reported the highest turnout rate for decades.

    Voter turnout reached 31 percent at midday, almost 10 percentage points higher than the election in 2002, said the Interior Ministry.

    This figure also marked the highest midday turnout rate for a number of decades.

    Low turnout in 2002 helped far-right politician Jean-Marie Le Pen qualify for the second round with incumbent Jacques Chirac.

    Although opinion polls have consistently put right-wing candidate Nicolas Sarkozy and Socialist Segolene Royal as the favorites to enter the run-off, the results remain highly unpredictable as centrist Francois Bayrou, third in opinion polls, may turn out to be a dark horse.

    Voter turnout in France's overseas territories was also higher than the 2002 first round.

    For the first time, overseas voters cast their ballots one day earlier than mainland France to avoid the frustration of knowing the results before going to the polls.

    Some 44.5 million voters are deciding which of the 12 candidates will succeed Chirac, who retires next month after 12 years in office.

    If none of the candidates can get more than 50 percent of the vote, which will probably be the case, the top two candidates will be in the run-off in two weeks' time.