The Croatian government said on Thursday it had awarded a licence to energy group INA for gas and oil exploration and exploitation on one block in the country's central and mountainous southern area.
It gave no financial details.
Earlier this year Croatia received one bid from INA for exploration in one block in the Dinarides region in a tender offering four blocks stretching over an area of 12,134 square km (4,685 square miles)..
The block awarded to INA covers an area of 2,698 square km.
INA's biggest shareholder is Hungarian energy company MOL with a stake of just under 50 percent. The Croatian government owns close to 45 percent of INA.
In August Croatia awarded four licences for on-shore exploration and exploitation in the largely flat northern areas.
The licences are valid for 30 years.
Croatia imports some 80% of its oil needs and around 60% of the gas it consumes.
(Reporting by Igor Ilic Editing by Alexandra Hudson)