In a statement issued on Sunday by its National Commissioner and Chairman, Information and Voter Education, Solomon Soyebi, the commission, however, appealed to residents to remain calm and peaceful during the rerun scheduled to hold on September 27.
The Returning Officer for the election, Professor Joseph Afuape, had declared the poll inconclusive.
According to the electoral body, the reason for the decision was because the number of cancelled votes were higher than the margin between the two top candidates.
The Peoples Democratic Party candidate Ademola Adeleke led the race with 254,698 votes, 353 votes more than his closest rival, Gboyega Oyetola of the All Progressives Congress.
The margin was, however, less than the 3,498 votes in the polling units where voting was cancelled.
INEC said, “ Based on the results collated by the returning officer, the margin between the two leading candidates is 353 which is lower than the number of registered voters in the affected areas.
“Extant law and INEC Guidelines and Regulations provide that where such a situation occurs, a declaration may not be made.
“In the light the foregoing, the commission met and decided that it will remobilise and return to the affected polling units on Thursday 27th September, 2018 to Rerun the elections, conclude collation and make a Return.
“We appeal to all stakeholders and particularly the people of Osun State to continue with the maturity and peaceful manner they have so far approached the elections”.
The commission stressed that only the votes of the electorate in the state would determine who would become the next governor.