Millions of French are voting in presidential elections, which are expected to see incumbent Nicolas Sarkozy lose his seat after just one term.
Sunday's vote will whittle down the field from 10 to two, with Mr. Sarkozy and his main opponent, Socialist Francois Hollande, expected to face each other in a head-to-head runoff May 6.
An estimated 28 percent of France's 44-million eligible voters had placed ballots within the first four hours of the polls opening.
Opinion polls before the election indicated that Mr. Sarkozy was trailing Mr. Hollande by several points.
Pollsters say Marine Le Pen on the far right and Jean-Luc Melenchon on the far left are expected to place third and fourth, respectively.
President Sarkozy, in office since 2007, has faced criticism for tough austerity measures aimed at reducing France's deficit.
Mr. Hollande has said if elected he would place a 75-percent tax on income above $1.3 million.
Under French law, the media are barred from announcing early or partial results before the polling stations close late Sunday .
On Friday, the conservative Mr. Sarkozy apologized for his actions in the early days of his five-year term. He said his mistake was “not understanding the symbolic dimension of the president's role.” But he defended his role in curbing French spending to help resolve the European governmental debt crisis. He said France would face more difficulties like debt-ridden Spain if it changes course.
Mr. Hollande is a veteran politician who headed the Socialist Party for several years. But he has never held a top government post.
During the campaign, Mr. Hollande blamed Mr. Sarkozy for France's unemployment rate of nearly 10 percent and called for sweeping changes to improve France's public finances.
President Sarkozy has said in interviews that the rule barring the announcement of early results is outdated. The law does not affect foreign-based media and the information is expected to be widely available on Twitter and Facebook well before official results are announced Sunday evening.
