Factbox-The candidates contesting Nigeria's presidential election

FILE PHOTO: PElectoral campaign posters of All Progressives Congress (APC) Presidential candidate, Bola Tinubu, with his running mate Kashim Shettima, are pictured at a bus stop, ahead of Nigeria's Presidential elections, in Lagos, Nigeria January 31, 2023. REUTERS/Temilade Adelaja

LAGOS (Reuters) - Nigeria will elect a new president on Feb. 25 to take over from Muhammadu Buhari in a contest pitting the old guard against a third-party candidate seeking to upset the established political order.

There are 18 candidates on the ballot, but only three are considered the top contenders.