China National Petroleum Corp (CNPC), the mainland's largest energy producer, is being drawn into the bloody Sudanese civil war with a dispute over its oilfields threatening a brittle peace in the African country. Discrepancies between the state-owned firm's oil production figures and the Sudanese government's data are increasing the risk of new fighting between rival factions fighting for control of the impoverished country. Under a peace deal struck five years ago oil riches have to be shared between the two sides based in northern and southern Sudan. According to human rights activists, tensions are being fuelled by suspicions the government in northern Sudan under-reported oil production to reduce its payments to the rebels in the south. The amount of unreported oil could power a major American city for a year. CNPC, the parent of PetroChina, is a vital link in China's search for oil beyond its borders. The energy-hungry mainland gets 5 per cent of its crude oil from Sudan and investment in oil production facilities there is seen as important for the country's energy security. 'There are already armies amassing on either side of the border, near the oilfields,' said Rosie Sharpe, a campaigner for Global Witness, an international non-governmental organisation. CNPC is the biggest equity partner in all but one of Sudan's operational oilfields, where thousands of mainland nationals work. Chinese firms like CNPC have an advantage over US firms in dominating Sudan's oilfields, as US firms would worry about damage to their image from investing in a country with human rights issues, said Antony Goldman, chief analyst of PM Consulting, a risk consultancy specialising in Africa. North Sudan is ruled by the Sudanese government while south Sudan is controlled by the Sudan People's Liberation Army. In 2008, five mainland oil workers were shot dead in the country, underscoring the risks of operating in a war zone. They were among nine CNPC employees who were kidnapped. A CNPC spokesman told the South China Morning Post he has no answer to Global Witness' concern that CNPC's published oil production figures in Sudan's Upper Nile State in 2009 was 12 per cent higher than those published by the Sudanese government. Global Witness said it has not received any reply to queries about differences in production data from either CNPC or Sudan's Ministry of Finance after raising the matter six months ago. 'The difference is 12 million barrels of oil, worth US$370 million and enough to power San Francisco for a year,' Sharpe said. 'While it is impossible to say which figures are correct, it is clear that both cannot be. 'The authorities in the north have not done enough to allay the suspicion by many southerners that they are under-reporting the volume of oil produced to transfer less money to the southern government due under the peace agreement.' Under a peace agreement signed in 2005 by the Sudanese government and the Sudan People's Liberation Army, oil production revenue is to be shared by the north and south. The oil-sharing agreement ends in January 2011, when a referendum will be held to decide whether south Sudan will unite with the north or secede. 'All the polls suggest there will be a landslide vote for independence. Given that the south has three quarters of Sudan's oil, it is difficult to see how such a split will not restart the conflict,' Sharpe said. One way to avoid civil war is to create a more transparent oil-sharing agreement between both sides, she suggested. 'Renewed conflict in southern Sudan threatens China's energy security, its investments and the thousands of Chinese workers in Sudan. It is in China's interest to use its influence in Sudan to help reduce the risks of conflict,' Sharpe said. China has become the world's sixth-biggest foreign investor and overtook the United States as Africa's top trading partner last year. CNPC's politically sensitive assets, including oilfields in Sudan and Iraq, have not been injected into PetroChina, which is listed in Hong Kong and Shanghai. Many US and European funds are forbidden by their own code of conduct from buying shares of PetroChina due to human rights issues, one analyst said. TIAA-CREF, a US pension fund, is leading a campaign to persuade companies to divest from PetroChina, the analyst said. TIAA-CREF plans to seek meetings with PetroChina, CNPC and other companies to persuade them to exit Sudan or try to 'end genocide' in Darfur, otherwise it will divest from those companies, Reuters reported.