Former vice presidentAtiku Abubakar will challenge incumbent Muhammadu Buhari for the Nigerian presidency early next year after winning the opposition Democratic Peoples Party primary, an AFP reporter at the vote said on Sunday.Abubakar, 71, won 1 532 votes, trouncing his main rival Aminu Tambuwal, the governor of northern Sokoto state who scored 693 votes at the party's convention in the southeastern oil hub of Port Harcourt."Thank you for choosing me," Abubakar said on Twitter. "It's a victory for all of us. The task to get Nigeria working again starts now," he wrote, even before final results were in.Twelve candidates were in the running for the DPP nomination, decided in the weekend primary by some 3 000 party delegates.Abubakar has already run for the presidency four times. He has amassed a huge fortune in the import-export business, as well as oil, agriculture and telecommunications.Nigerians will elect governors and lawmakers as well as the president in elections set for February and March next year.* Sign up to News24's top Africa news in your inbox: SUBSCRIBE TO THE HELLO AFRICA NEWSLETTERFOLLOW News24 Africa on Twitter and Facebook.