This dissertation examines joint ventures of a large oil and gas group operating in Angola: it uses a case study with the aim of confirming whether their jointly controlled assets and jointly controlled entity are similar in their economic essence. We address this issue by understanding the legal and economic environment of those two types of arrangement. The results of the case study suggest that the two arrangements have legal and economic similarities, mainly due in both settings to the following: the venturer/investor held a veto power for major decisions; this veto power is bound by a written contractual mechanism; the venturer/investor has an active role in the activity of the arrangement; and the venturer/investor is implicitly obliged to fund the operations of the arrangement. The results of the case study also suggest that the accounting treatment of the joint arrangements should be discussed in conjunction with the other types of arrangement, i.e., the definition of the joint arrangements should be part of a framework for investments made by the investor in any entity.