Former Credit Suisse chief Tidjane Thiam and former President Laurent Gbagbo are barred from contesting next month's presidential election in Côte d'Ivoire, although Gbagbo's ex-wife, Simone Gbagbo, will be able to run, an official said on Monday.

President Alassane Ouattara, 83, announced in July he would seek a fourth term in the world's top cocoa-producing nation.

Ouattara's government has promised a peaceful vote.

Thiam, the designated candidate of the main opposition party PDCI, was excluded after a court ruled in April that he should be removed from the electoral roll because he was a French national when he registered.

Five presidential candidates cleared to vie

Côte d'Ivoire law states that candidates must be Côte d'Ivoire citizens and cannot hold another nationality.

Monday's decision, announced by Constitutional Council President Chantal Nanaba Camara, validated five candidacies out of 60, including Ouattara's.

It came just over a month before the official campaign period begins on October 10.