Occidental Petroleum Corp is in talks about a potential sale of energy assets in Africa and the Middle East to Indonesia’s state-owned PT Pertamina, people with knowledge of the matter said. Pertamina is negotiating the acquisition of oil and gas stakes in countries including Ghana and the United Arab Emirates, according to the people. It has been discussing a purchase price of about $4.5-billion for the assets, the people said, asking not to be identified because the information is private.