LONDON (Dow Jones)--Falkland Islands-focused oil and gas explorer Rockhopper Exploration PLC (RKH.LN) Tuesday said Executive Chairman Pierre Jungels bought another 23,350 shares in the company. The purchase follows results published last week from a laboratory analysis of oil samples from its Sea Lion discovery in the North Falklands Basin, which confirmed the oil is a medium-grade crude. The discovery has yet to be formally declared commercial. Rockhopper said Jungels bought the shares at 298.5 pence each, taking his total holding to 889,424 shares, or just under 0.5%. Non-executive director Chris Walton also bought shares, picking up 8,300 at 297.625 pence. At 0944 GMT, shares in Rockhopper were up 15.25 pence, or 5.1%, at 313.25 pence, outperforming a 0.6% higher Alternative Investment Market. News of the share purchases comes ahead of results from another exploration well, this time in the South Falklands Basin, from Falkland Oil & Gas Ltd. (FOGL.LN), due next week. Malcolm Graham-Wood, director of broking at Westhouse Securities, said Rockhopper remains the preferred pick of the small group of explorers searching for oil off the Falkland Islands. -By Jason Douglas, Dow Jones Newswires; 44-20-7842-9272; [email protected] (END) Dow Jones Newswires July 06, 2010 06:01 ET (10:01 GMT)