Iran has begun gas exports to supply Iraq’s power plants, four years after an agreement to transport the fuel from the giant South Pars gas field was signed.

Iran will start with an initial supply of 7 million cubic metres a day of gas to Iraq’s Sadr, Baghdad and al-Mansuriya power stations, reported Shana, the state news agency aligned with the petroleum ministry.

The supply is expected to be increased to 35 million cubic metres in the summer months.

The agreement to supply Iraq through the 270-kilometre pipeline signed in 2013 is expected to bring Iran annual revenues of around $3.7bn.

Iraq’s power stations such as the 728MW Al-Mansouriya have remained idle because of gas shortages.

Iran halted electricity supplies to Iraq in January citing Baghdad’s failure to pay off accumulated debts of around $1.2bn

Tehran said last month that electricity supply to its neighbour had resumed despite Baghdad having repaid only $50m.

Following the US invasion of Iraq, the war-ravaged country’s utilities infrastructure has remained not been upgraded, prompting power outages and protests against the government across various provinces.