Nigeria will clear unpaid bills worth $5.1 billion for oil production joint ventures (JVs) piled up over many years under a deal signed on Dec. 15.

The deal would unlock new investment in the OPEC member country, Oil Minister Emmanuel Ibe Kachikwu said in a speech at the signing ceremony, adding the repayment would take place over the coming five years.

Oil majors that agreed to the deal include: Royal Dutch Shell Plc (NYSE: RDS.A), Chevron Corp. (NYSE: CVX), Total SA (NYSE: TOT), Eni SpA (NYSE: E) and ExxonMobil Corp. (NYSE: XOM).

Kachikwu said the oil majors had given Nigeria a discount of $1.7 billion, lowering the original amount from $6.8 billion.

The agreement would also ensure that future Nigerian payments to production JVs with oil majors would be paid in time, he told reporters after the signing.

Kachikwu also said that Forcados exports would resume soon, without giving any more precise information. The grade has been under force majeure since February after multiple attacks on the pipelines that carry it to the export terminal.