French citizens in the country's overseas territories have begun casting ballots in a presidential runoff election to determine who will succeed President Jacques Chirac.

Saturday's early voting comes a day before voters in mainland France cast their ballots for either conservative Nicolas Sarkozy or Socialist Segolene Royal.

Early voting opens in the tiny island territories of St. Pierre and Miquelon off Canada's east coast. Voting also will take place Saturday on the Caribbean islands of Martinique and Guadeloupe, and in French Polynesia in the southern Pacific Ocean.

Voting starts a day early in French overseas territories, where there are about one million voters, to compensate for the time difference with mainland France.

The latest public opinion polls indicate Sarkozy leads Royal by at least nine percentage points.

Sarkozy and Royal were the top two finishers in the first round of French presidential elections on April 22.

Sunday's winner will succeed President Chirac, who is retiring from politics after 12 years in office.

Some information for this report was provided by AFP and Reuters.