Three foreign companies have bought documents to take part in a tender for awarding a licence for oil and natural gas exploration in the Bulgarian section of the Black Sea, the energy ministry said.
Two of the companies are European and the third one is US-based and they are all among the leaders in the sector, the ministry said in a statement, providing no further details.
Bids can be placed by May 27, the ministry said last month.
The five-year licence will cover the 4,032 square kilometres Block 1-22 Teres. In the event of commercial discovery, the concessionaire will be automatically granted permission to produce from the field.