(ShareCast News) - Oil and gas investment company Paternoster Resources' pre-tax profit increased as the company sold shares in existing mining investments.For the six months ended 30 June, profits after tax rose 61.5% to £443,170, compared to the same period in last year.The investment portfolio made "good progress" as net assets increased by 15% to £3.39m or 0.37p per share due to an increase in the Metal Tiger share price and good performance from its other investments including Plutus PowerGen.The majority of the portfolio comprises of listed investments and cash, which represent 195% of market capitalisation.The AIM-listed company also gained profits by selling 15m of shares held in Metal Tiger for £650,000, and 20m shares in Plutus PowerGen for £150,000 that were held under option, which contributed to the company's cash resources. Convertible loan notes of $495,365 held in Alecto Minerals were converted into 434m shares.Total cash held at the end of the June was equivalent to 75% of market capitalisation.Chairman Nicholas Lee, said: "The company's investment portfolio continues to make very good progress, and we have taken the opportunity during the first half of 2016 to realise some of the very significant gains made by our investments."This demonstrates that not only can we achieve good investment returns but that we can also realise these returns. This performance, however, is not being reflected in our share price and we are therefore now in the process of implementing certain strategic steps to address this issue."Shares in Paternoster Resources were up 15.35% to 0.179p at 1417 BST.