The two Africans left in the race are Nigeria’s Ngozi Okonjo-Iweala, Kenya’s Amina Mohamed.
They proceed to the second selection round with South Korea, the UK and Saudi Arabia.
The new leader is expected to take office in November.
The WTO sets the rules for global trade and adjudicates in trade disputes between nations. It is also, according to its website, supposed to “open trade for the benefit of all”.