Reuters reported China's National Development and Reform Commission saying on its website that approval for the acquisition had been granted in June, although no further details are currently available.
Industry officials have been quoted saying that PetroChina and Japan's largest refiner Nippon Oil were expected to have finalized a deal by end-June which would see PetroChina buy up a 49% stake in the 115,000 barrels per day (bpd) Osaka refinery.
PetroChina is said to have, through its trading arm Chinaoil, in recent years been involved with Nippon Oil over several crude processing deals, buying up surplus production capacity owned by Nippon Oil.
According to Reuters, this latest Osaka acquisition will allow PetroChina to control all of the refinery's crude supply and product offtake.
PetroChina, which in recent weeks through another acquisition became the controlling shareholder in Singapore Petroleum Company (SPC), last week made a mandatory cash offer for the remaining shares in the company.
PetroChina International (Singapore) Pte. Ltd., recently acquired a 45.51% stake in SPC, representing 234.5 million shares, for S$1.47 billion ($1.02 billion) from Keppel Corporation's Keppel Oil & Gas Services Pte Ltd (KOGS).
SPC has a 50% interest in Singapore Refining Company Private Limited, one of the three major petroleum refiners in Singapore. SPC also conducts terminalling and distribution and trading of crude and refined petroleum products.