Rockhopper Exploration, the Aim-traded company looking for oil off the Falkland Islands, saw its shares jump almost 13 per cent on the back of encouraging geological data.

The company, which floated on the junior market in August last year at 42p, said yesterday that its analysis of information from new 2-D seismic data combined with electromagnetic mapping, a relatively new technology, has identified a prospect with potential recoverable reserves of 100m barrels.