State-controlled Chinese oil and gas group PetroChina may surpass ExxonMobil as the world's most valuable quoted business, the Financial Times reported. Last year, the company's oil and gas reserves totaled 20.5 billion barrels of oil equivalent, compared to Exxon's 22.8 billion barrels, according to a new report from consultancy PFC Energy. But a new offshore oil field discovered in May and thought to hold 7.3 billion barrels of oil may result in the company's reserves to be revised upwards. Citigroup analysts speculated that PetroChina's A-share listing launched next month will coincide with announcements of additional oil and gas discoveries. On Monday, PetroChina overtook General Electric to become the world's second-highest-valued listed company on a rise of its Hong Kong-listed unit's price.