HANOI, Oct. 14 (Xinhua) — The Asian Development Bank (ADB) and Vietnam have signed a 231.3-million-U.S. dollar loan agreement to enhance the power transmission network in the country's south, the ADB Vietnam said in a statement on Friday.

The loan is the third tranche of a 10-year Power Transmission Investment Program, which was approved by the ADB in 2011, and expected to be completed in 2020.

Tranche 3 will add 60 km of 500 kV, 64 km of 220 kV, and 3,700 MVA of transmission capacity in southern Vietnam, enabling electricity transmission from the power plant cluster in the southwest region to the national grid system, and improving the reliability and stability of power supply to major economic centers in the southern region, said the statement.

The last tranche, tranche 4, which is being prepared and is expected to be approved in 2017, will focus on a 500 kV transmission line and substations in the southern region.