Côte d'Ivoire's former Trade Minister Jean-Louis Billon said he is seeking to represent the opposition PDCI party in October's presidential election after former Credit Suisse chief Tidjane Thiam was excluded from the final list of candidates last week.

The question of who will carry the mantle of the main opposition party risks adding to tensions in the world's top cocoa producer, which has a history of election-related violence including a brief civil war after the 2010 presidential contest that killed about 3,000 people.

In an interview with Reuters in the commercial capital Abidjan, Billon, 60, blamed party officials for the handling of legal challenges to Thiam's candidacy and did not rule out the possibility of representing another party, though he said it was too early to make such a move.

"I am asking for the PDCI's support," he said.

'Lack of preparation'

"It's a shame that (PDCI) President Thiam was eliminated, but it was the result of the lack of preparation of certain party officials that led to his elimination. That's why you always have to have several strings to your bow, especially when you're in politics."

The electoral commission published its final list of candidates last week, excluding Thiam, who denounced the decision as a sign of the "abandonment of democracy".

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

Thiam renounced his French citizenship in February in order to meet eligibility conditions for the election.

French national when Thiam registered

But a court in Côte d'Ivoire ruled in April that Thiam should be removed from the electoral roll because he was a French national when he registered. Thiam told Reuters after that decision that he planned to fight on and run anyway.

The notion of Côte d'Ivoire identity was at the heart of past violence in Côte d'Ivoire, and some fear lingering questions over Thiam's nationality in the run-up to the vote risk pushing those tensions back to the surface.

Incumbent President Alassane Ouattara himself was barred from seeking the presidency over what opponents said were his foreign origins before he finally won election in 2010.

Ouattara, 83, has not said whether he will run again this year.

Lifting restrictions on dual nationality

Billon told Reuters that if elected he would endorse a law to lift restrictions on dual nationality.

"You have thousands of Côte d'Ivoire citizens who live abroad, who have made their lives abroad, and who end up having dual nationality," he said.

Billon also said he would trim the civil service, crack down on corruption, promote private sector investment and move more government offices to Yamoussoukro, the administrative capital.

He said it was time for Ouattara and other politicians of his generation to leave the scene.

" Côte d'Ivoire will change. I think our elders have had their day," he said.