* Fire caused by leak of propylene
* Fire extinguished, no casualties (Updates with fire put out)
SHANGHAI Aug 4 (Reuters) - A fire broke out at a PetroChina refinery and petrochemical plant on Monday but was later put out and no casualties were reported, government and company officials said.
The plant near Lanzhou city in the northwestern province of Gansu is one of the country's oil refining hubs. It operates crude refining capacity of just over 200,000 barrels per day and also an affiliated petrochemical complex.
Initial investigation showed the fire, which broke out at 8.39 a.m. (0039 GMT), was triggered by a leak of propylene at a 300,000 tonne-per-year air separation unit, the government of Gansu said on its website (www.gansu.gov.cn).
The fire was put out at 1:45 p.m., it said.
It was not immediately clear if other main production facilities at the plant were affected by the fire.
On Saturday, China suffered its worst industrial accident in a year when an explosion killed at least 69 people and injured more than 120 at a factory in the eastern province of Jiangsu that makes wheels for U.S. carmakers, including General Motors.