An African island nation offered oil companies control of as much as 85% of three offshore blocks. Only two investors came forward.

São Tomé and Príncipe has now reportedly rejected every bid submitted in its latest licensing round, delivering another setback to the Central African country’s decades-long search for a commercially viable oil discovery.

Brazilian energy giant Petrobras and Nigerian-owned Oranto Petroleum were the only companies to submit offers for Blocks 7, 8 and 9 before the June 30 deadline, according to specialist industry publication Upstream.

The National Petroleum Agency, known as ANP-STP, reportedly decided that the bids did not provide sufficient diversity or competition to proceed with awards.

The result is a striking one for one of Africa’s smallest economies. São Tomé had offered participating interests of up to 85%, terms promoted as unusually generous for an offshore licensing round in sub-Saharan Africa.