US-based oil and gas corporation Exxon-Mobil will return three upstream licences to the Indonesian government, as the assets have failed to deliver sufficient value. The licences pertain to the offshore Surumana and Mandar oil blocks located in the deep waters of the Makassar Strait and the Gunting block located in East Java. ExxonMobil won the production sharing contract to develop the Surumana block in 2006: it had an 80 per cent stake in the block, with the remainder held by Malaysia-based Petronas. The firm won the concession rights for the Mandar block in 2007, in which it holds 100 per cent stake. The firm also holds 100 per cent stake in the Gunting block.