PetroChina agreed to pay US$1 billion for a stake in Singapore Petroleum, the Wall Street Journal reported. The purchase of the 45.5% stake in the oil refiner from current holder Keppel Corp is expected to lead to an offer for the entire company. Once the deal is approved by Chinese regulators and closed, it will trigger a general offer for the entire business under Singapore’s corporate takeover law. The offer values the entire company at US$2.25 billion. Singapore Petroleum has interests in Australia, China, Indonesia and Vietnam. The company had revenues of US$7.7 billion in 2008.