Canada's Vermilion Energy will drill its first two exploration wells in Croatia in June, a senior official from the company said on April 15. Vermilion won four licenses in 2015 for oil and gas exploration in Croatia's flat northeastern areas and the drilling will take place on one of these.

"Although we see evidence of gas charge from the new seismic data we have acquired, we'll not know for sure whether any of this is commercially producible until after these initial wells are completed," Bryan Sralla, who heads the unit for central and eastern Europe, told Reuters.

He added that would probably be during mid to late July.

Croatia is currently running two new tenders for oil and gas exploration in the north and in the mountainous southern region. . They are open until June and September, respectively.

Sralla said Vermilion was still considering whether to participate.

"Our team is evaluating the potential of all the Croatian licenses on offer, but we have not yet made a decision whether we will bid on any," he said.

"Our internal executive review is scheduled for late May. I'm hopeful our team will identify some potential," he added.

In an interview with Reuters last week a senior official at Croatian energy firm INA said it planned to bid for several exploration blocks in the north, but was still considering options for the south.

Vermilion also has a presence in Slovakia and Hungary.

Sralla said the company planned to drill four wells in Hungary this year, two in partnership with Hungary's MOL , and four wells in Slovakia in partnership with Slovakian energy company Nafta.

"We see encouraging signs of natural gas potential in these countries," he said, adding that the drilling results were likely to be announced in the early autumn.

Sralla also said Vermilion could expand into other central and eastern Europe countries as the company was evaluating investment opportunities across the region.