The licence makes them the legal owners of the Keta Delta block, located in the Volta Region.
The acquisition makes Swiss African Oil and PET Volta the first to explore for oil onshore Ghana.
The Keta Delta block licence was awarded following ratification by Parliament of a joint venture between the Government of Ghana, the Ghana National Petroleum Corporation, Swiss African Oil Company Limited and PET Volta Investments Limited.
The new block covers an area of 3,000 square kilometres and it is envisaged that the operations would provide employment and stimulate local development in the region.