Indonesian company Indelberg Makmur Petroleum (IMP) will file an appeal against national oil company Pertamina's intent to terminate a co-operation agreement related to the Benakat Barat field in South Sumatra.

IMP, formerly known as Benakat Barat Petroleum, received a letter of termination from Pertamina, according to one of IMP's major shareholders Interra Resources.

Interra did not disclose why the termination had occurred, but said IMP will file an appeal against the letter of termination.