Rivals China Petrochemical Corp (Sinopec) and the China National Offshore Oil Corp (CNOOC) are working together for the first time to secure supplies of natural gas, the Wall Street Journal reported. The agreement focuses on natural gas supplies, reserves and construction of natural gas pipelines. The government believes annual domestic demand for natural gas will reach 100 billion cubic meters by 2010 from around 65 billion cubic meters in 2005. The two companies may use their advantages to form an alliance in domestic and overseas investment in natural gas distribution, infrastructure and acquisition of overseas assets. Sinopec made a big gas find last year and is building a natural gas pipeline from the southwest to Shanghai. CNOOC supplies gas from the East China Sea to Shanghai. The two companies may need to coordinate sales and pipeline networks in the city.