Nigeria, Sept. 22 -- Nigerian could look the way of Eurobonds to tap new debt the government needs to bridge a gap in its spending plan for 2021.

Offers for a similar issuance on Tuesday were way higher than what was put out, demand dwarfing the debt size four times over, an outcome the debt office designated "one of the biggest financial trades to come out of Africa in 2021."

The $4 billion sourced abroad after the interest from investors there surpassed the $3 billion originally intended is causing government to bet the international sovereign bond market would be healthy for its borrowing ambition this year.

"We will monitor the markets while still exploring other sources," Patience Oniha, the Debt Management Office (DMO) chief told...