BP and Royal Dutch Shell are looking at a $4bn (£2.5bn) stake in a gas field in Mozambique, a sale that would confirm East Africa as the hottest growth area in world energy. Eni, the Italian oil and gas giant, has claimed that the Area-4 gas find is the biggest in its history, but is looking to sell down its 70 per cent stake to find a partner who can help shoulder the capital expenditure. There has been a huge surge in interest in the region, and several parties are understood to have flown to Milan to discuss buying a 20 per cent share of the field. Even taking the lower estimates of similar deals in the region, and ignoring the probable premium to work with an established player like Eni, that stake should be worth more than $4bn. Most of the major players have been late to get into East Africa, and will now have to take over or form joint ventures with smaller explorers who gambled that there were big finds to be had in the region. Shell\'s chief executive, Peter Voser, right, has already shown his interest in the region with a near-£1bn bid for London-listed Cove Energy, which is significant for holding a 8.5 per cent stake in another field off the coast of Mozambique. However, Thailand\'s PTT has made a higher bid, while two Indian companies are also interested. It is thought that this sale process should be concluded in the next month, though there could still be a surprise winner as 25 companies, including BP, went into the \"data room\" – where firms show sensitive financial and operational information to potential bidders. It is understood that at least 45 companies applied to enter the process. BP has been linked to a potential tie-up with Ophir Energy, a well-regarded Ftse-250 group that has potentially substantial discoveries off both the west and east coasts of Africa. It is understood that BP did talk to the company about taking a stake in a Tanzanian offshore field, but that Ophir wants to wait until it has more detailed information on its find, in the hope that the results will force a higher price later in the year. Even then, BP cannot be guaranteed a stake, as Ophir will likely take note of the competitive tension taking place in other sales processes and run an auction. Shell and BP will also find they are in a highly competitive process to team-up with Eni. Paris-based Total has been reported as being among the oil producers and utilities also interested in bidding.