PetroChina has announced it has reached a preliminary agreement with Qatar Petroleum International and Royal Dutch Shell regarding the possible construction of a new integrated petrochemical facility within China.

Under the arrangement, China's national firm will take a 51 per cent controlling stake in any future development, with the two other companies to each have a 24.5 per cent interest.

"This is just a letter of intent, not a contract," stated Liu Xiaowei, a spokesperson for Shell China in Beijing, adding that the deal will also entail further research into the location of further Chinese oil supplies.

Though the exact details of the plans, including the likely location of the new plant as well as the level of investment involved, have been confirmed, it is believed that this marks the latest step in China turning to Qatar, which is sees as still relatively under-developed, as it looks for solutions to its long-term energy supply problems.

Currently Shell is working with the China National Offshore Oil Corporation in developing a petrochemical refinery in the Guangdong province in the south-east of the country, with construction expected to be completed in the autumn.