Mainland oil firms CNOOC and China Petrochemical Corp are lobbying Royal Dutch/Shell not to block their gas field acquisition deals in Kazakhstan - but the global giant has not ruled it out. However analysts expect the deals, which were struck in March, to proceed smoothly. They have dismissed the latest development as a public relations exercise for the oil companies. CNOOC and China Petrochemical - parent of listed China Petroleum & Chemical (Sinopec) - have each agreed to buy a 8.33 per cent stake in Kazakhstan's North Caspian Sea project from BG International (British Gas) for US$615 million. Qiu Xianghua, vice-president of Sinopec International Petroleum Exploration & Production, said its chairman had written to Shell's top management and met them in Europe in an effort to persuade them against pre-empting the deal. The Kazakhstan project's original investors - Shell, ExxonMobil, ConocoPhillips, France's TotalFinaElf, Italy's ENI-Agip and Inpex of Japan - have the right to pre-empt CNOOC's purchase by May 9 and China Petroleum's by May 19. CNOOC chief financial officer, Mark Qiu Zilei, said it had written to the consortium members asking for 'favourable consideration'. Mr Qiu said China's friendship pact with Kazakhstan and status as one of the world's largest oil markets, as well as Sinopec's experience in shallow water oil drilling, would be favourable to the project. Shell spokesman Nick Wood said the company was 'considering its position'. HSBC Securities oil and gas analyst Gordon Kwan said the international oil firms were unlikely to exercise their pre-emption rights because it would upset China and Kazakhstan. He said it was typical for firms to use media opportunities to send subtle messages to negotiation partners. 'As CNOOC and Sinopec are in talks to sell a stake to Shell in their Xihu Trough gas field project, it was Shell's way of saying 'if you don't give me a good deal [in Xihu], I can block you in the Kazakhstan project',' he said. 'It is also a way to say 'I'm really doing you a favour by giving up the right to block you'.' The lobbying efforts of CNOOC and China Petroleum, and Shell's refusal to rule out blocking the purchases, would also make the deals appear more attractive. 'It's a win-win situation for all parties,' Mr Kwan said. UOB Kay Hian analyst Michael Lee said: 'I don't think Shell would do such a foolish thing as block the deals. 'Even if Shell exercises its pre-emptive right and becomes the largest shareholder it will still not be the project operator, which is ENI-Agip.'