PetroChina Co. Ltd.’s shares nearly tripled in its first day of trading in China, making it the world’s first company worth more than $1 trillion on Monday, the Associated Press reported.

State-owned PetroChina, a unit of state-owned China National Petroleum Corp., is the country’s biggest oil and gas producer. Its initial public offering in Shanghai of 4 billion shares raised 66.8 billion yuan, or $8.94 billion — a record for a mainland exchange. The company’s total market capitalization grew to just over $1 trillion; in comparison, Exxon Mobil Corp.’s capitalization stands at $488 billion.

However, more than 85 percent of the shares outstanding — 157.9 billion shares — are held by China National Petroleum, and it’s doubtful they will trade in the market soon. PetroChina’s new shares listed in Shanghai surged to $5.90 Monday and almost tripled the IPO price of $2.24.

PetroChina’s strong performance was expected; shares tend to climb in their trading debuts, and Chinese investors are eager to invest in highly valued companies.