(ShareCast News) - Prospex Oil & Gas said it has achieved a major milestone as Poland's Ministry of Environment approved the company's plans to drill the onshore Boleslaw-1 well.The well, in the 1,150 sq km Kolo Licence, is targeting gas in an active petroleum system and remains on track to be drilled in the fourth quarter of 2016.Prospex said the next step would involve filing the final application for the drilling permit, which was expected to be completed shortly.Non-executive chairman Bill Smith said the approval was another "major milestone" achieved."In tandem with the progress being made at Kolo, we continue to evaluate other opportunities which match our investment criteria," he added.Kolo is 100% owned by Strzelecki Energia Sp z.o.o, a wholly owned subsidiary of Hutton Poland Ltd in which Prospex holds a 49% stake.At about 10:26 BST, shares in Prospex were down 0.63% to 2.36p.