German oil firm Wintershall  said it is struggling to return production in Libya to levels from before the civil war, with difficulties finding contractors, and despite its vast resources, it is also ruling out exploring for more hydrocarbons.The company's Chief Executive Rainer Seele told Reuters that Wintershall, the oil and gas unit of chemical giant BASF is not finding the conditions for foreign oil firms in Libya attractive enough.Wintershall was reported to be the second-largest foreign oil firm in Libya before the ousting from power of the former dictatorial regime of Muammar Gaddafi in 2011. The largest wasItaly's ENI . Before the revolution, Libya accounted for three-quarters of its total oil output.Since the end of the conflict Wintershall has been trying to return to its pre-war level of production, targeting an output of 100,000 barrels per day this year, but right now Seele says it's output is around 80,000 barrels per day on average and it will be difficult to reach the prewar level of 100,000 barrels per day this year, as it had earlier expected.“It is a challenge but we are working for that,” Seele told Reuters, "It is difficult to give a certain date (but) we would like to get to 100,000 barrels as early as possible,” he added.A year ago, the main challenge was Libya's old pipeline system, which was preventing the firm from transporting its crude from the Libyan desert to port. But that problem was partly solved after Wintershall helped build a new pipeline, which it says will be in operation soon. Seele added that the difficulty now is finding the required contractors. “The service industry is not at the same level that it was before the war ... This is a limit,” he said.Talking about security in Libya, he said the the crisis in the Amenas gas plant in Algeria has not affected Wintershall's installations.”I definitely have not seen a change. We had already increased our security system in Libya because of the civil war in 2011,” he added.He ruled out exploration in Libya, as long as the conditions offered to foreign oil companies were not favourable. “The framework really is not supporting additional exploration. The contractual base needs to be improved. I am not hungry for exploration right now,” he said.Seele added that Wintershall will remain in Libya, the only country in North Africa where his company has a presence.