Italian energy firm Eni apparently plans to give up all of its Polish shale gas permits because of tough geology and an unclear regulatory environment, the same issues that have already pushed other foreign firms to end drilling in Poland. Only a few years ago, the country was touted a few years ago as having the best shale gas prospects in Europe.

The Italian company initially owned three licenses in the north of the country. In a statement to the news agency Reuters, the Polish environment ministry said two of the licenses had already expired with no plan from Eni to renew them. While it said it had no information on the third permit, which runs until 2018, industry sources told Reuters that Eni would pull out of the third permit as well, ending its shale gas activities in Poland entirely. The company has declined comment.

Eni's expected move is another blow for Polish shale gas, which the government hopes will help cut Poland's dependence on imported gas from Russia. Over the past few years, investor enthusiasm has waned because of a downward revision of the size of potential resources, uncertainty about the legal framework and difficult geological formations for shale gas drilling.

Oil firms, including Marathon Oil, Talisman Energy and Exxon Mobil, have also quit Poland, the latter citing "disappointing results." Eni's departure would leave Chevron as the only energy major with Polish shale gas concessions. Smaller players with strategic interests may have the needed flexibility, however.

Talisman in 2010 signed a farm-out agreement with San Leon Energy, based in Dublin, Ireland, giving the Irish firm a 30% working interest in three blocks of the Baltic Basin. The company, which works together with Warsaw-based United Oilfield Services and Haliburton of the U.S., describes itself as a significant player in the Polish shale gas market, with interests in six license areas in addition to the Lewino-IG 2 concession near Gdansk. Through the farm-out agreement with Talisman, San Leon said it sees potential for "substantial revenue generation" in Poland.

In November 2013, acting Polish environment minister Piotr Wozniak told a press conference that commercial exploitation of shale gas could begin in 2014, rather than 2015, as originally expected. The remarks came after San Leon said its drills far exceeded expectations, and British company 3Legs Resources said its own drills carried out with ConocoPhillips in the Baltic Basin were more than encouraging.