BP has taken a 20% stake in China Aviation Oil (CAO), the troubled firm that imports most of China's jet fuel.
BP has a growing stake in the Chinese oil industry
The UK oil giant paid $44m (£25.4) for the stake as part of a rescue plan involving CAO's parent company and state-run Singaporean investor Temasek.
CAO collapsed a year ago after running up a $550m trading loss betting on the future price of oil.
Singapore-based CAO supplies oil to more than 100 Chinese airports and is majority owned by the Chinese state.
BP's stake in the $130m rescue package will give the world's second-biggest oil company a greater presence in China's tightly controlled oil market, which is the fastest growing in the world.
BP already holds a 24% stake in South China Bluesky Aviation Oil, which supplies jet fuel to 15 Chinese airports.
The British oil company is one of the biggest foreign investors in China, where it employs more than 3,000 staff.
It runs around 1,000 petrol stations in China after signing deals with two of the country's main oil companies, Sinopec and PetroChina.