President Energy is to become the operator of the 'promising' Hernandarias Block in the Chaco region of Paraguay, after being granted a farm-in of up to an 80 per cent interest.The farm-in, which is still subject to government and regulatory approvals, was granted at no cost to President, though the firm will fund the first $17m of a work programme.If approved, the AIM-listed company would operate a contiguous land block of 34,507 km squared, covering almost the entire prospective Pirity Rift Basin. It said that this would represent a "basin controlling position" in the Chaco region."The Hernandarias Block is a promising one, in which President has a significant level of understanding based on its work in the Pirity and Demattei Concessions," said Chairman Peter Levine.Hernandarias is said to contain the same Paleozoic play system that delivered "very significant" reserves in the adjacent Andean mountain front of Bolivia and Argentina. These reserves totalled 14bn barrels of oil equivalent.The company said: "It is contemplated that on completion of the agreement, President will commence prospect specific seismic in the Hernandarias Block following award of the Concession Law with a view to drilling the first Paleozoic structural test on the Hernandarias Block within the three-year work programme period."The stock was up 5.1% at 36p in early trading on Friday, close to a 52-week high.BC