* Nigerian minister credited with revival of agriculture sector
* African nations getting more financing from China, Eurobonds
* Pan-African lender must stake out its niche (Releads with Nigerian candidate's victory, writes through)
By Joe Bavier
ABIDJAN, May 28 (Reuters) - Nigeria's Agriculture Minister Akinwumi Adesina won an election on Thursday to become the new president of the African Development Bank (AfDB), a post that will see him guide the institution through Africa's increasingly complex financial environment.
During six rounds of voting, Adesina defeated seven rivals from across the continent. He won around 60 percent of the votes by the Bank's board of governors in an election held in Ivory Coast, where the AfDB is based.
Adesina will take over from the current president, Donald Kaberuka of Rwanda, to become the 50-year-old body's eighth leader.
"I want to assure you that, as president of the Bank, I will be a responsible president," he said in a speech following his victory. "I will be focused and I will work with you to build upon the tremendous work of President Kaberuka."
A development economist with a PhD from Purdue University in the United States, the 55-year-old Adesina arrived at Nigeria's agriculture ministry in 2011.
In the process he took over an agriculture sector left neglected for decades as Africa's top oil producer became increasingly dependent upon petroleum revenues.
Under his stewardship, food production increased by 22 million tonnes and food imports dropped more than a third, in an agricultural revival the government claims created around three million jobs.
When Kaberuka finishes his term on Sept. 1, Adesina will take the helm of a financial institution at a crossroads.
The Abidjan-based bank was founded in 1964 to provide capital to foster economic development and alleviate poverty in its member states. It is financed by both Africa nations and shareholder countries outside the continent.
Recent years have seen a huge jump in lending to Africa from non-traditional partners, particularly China. And since 2011, more than a dozen African countries have issued their first international sovereign bonds.
"The bank has had a 10 good years, but the key now is to stay in the game," said one AfDB executive director. "We have to be relevant and do that by doing the things that other (commercial and development) banks can't."
Insiders said member states are divided on whether the AfDB should further concentrate on attracting private financing to infrastructure projects or move into new areas, including helping poorer nations get access to international debt markets.
The bank estimates that Africa needs annual infrastructure investment of around $100 billion over the next decade.
"Infrastructure financing is key," Ivory Coast's Budget Minister Abdourahmane Cisse said. "Not only infrastructure at a local level, but infrastructure for regional integration."
The AfDB's lending capacity meets only a small fraction of that demand, however, and the bank has compensated by playing on its `AAA' credit rating to attract private financing to projects.
"I am confident that my successor will be able to take the Bank to the next level," Kaberuka told Reuters in an interview soon after Adesima's election.
Additional reporting by Ange Aboa; Editing by James Macharia and Susan Fenton, Larry King