JAKARTA (Reuters) - Indonesian President Joko Widodo, who won election on a vow of clean government, said on Wednesday he would have to find new people to fill some of his Cabinet posts after the anti-graft agency rejected eight of the people he picked.

Mr Joko has tried to steer clear of the traditional trading of Cabinet posts for political support and has said he wants a ministerial team dominated by professional technocrats. He took the unprecedented step as president of submitting his list of candidates to anti-corruption agencies for vetting before announcing the team.

"Yesterday, we were told by (anti-graft agencies) ... there were eight names that weren't allowed," Mr Joko told reporters in his first news conference as leader of Southeast Asia's largest economy.

"Of course we have to change. If we don't, who will fill the posts?" he said. He declined to identify the candidates the anti-graft agencies had flagged as problematic.

Mr Joko had originally planned to announce his cabinet of 33 ministers on Tuesday, the day after his inauguration. He has said his team would be made up of 18 technocrats and 15 political appointees. It was not clear when an announcement would be made.

"Everyone wants us to work quickly but what happens if we are mistaken? We need to be quick, but also correct," Mr Joko said.

All eyes are on the Indonesian leader's choices for the main economic ministries. They will inherit problems in Southeast Asia's biggest economy ranging from a widening current account deficit and cooling investment to the slowest growth since 2009.

"The market hopes that in ministries related to the capital market-like finance ministry and the state-owned enterprises ministries-will be run by technocrat individuals," said Mr Harry Su, head of research at Bahana Securities.