Pan Andean gained on news that the oil and gas group received a £18m takeover offer from Toronto-listed peer Petrominerales.Petrominerales has offered to buy the shares for 15 pence each and one share of Hydrocarbon Exploration for every one Pan Andean share held. Hydrocarbon Exploration is a newly formed, unlisted company into which Pan Andean will transfer its non-Colombian and non-Peruvian assets. Hydrocarbon Exploration will initially be an unlisted company but Pan Andean said it anticipates re-listing the business 'in due course'.'For some time now, we have been attempting to unlock the value of our assets. This opportunity values Peru and Colombia at roughly £18m whilst shareholders would also retain their interest in our Bolivian and US assets,' said chairman John Teeling.