(Corrects typo in 1st paragraph to read "least", not "last".)
BEIJING, March 30 (Reuters) - China's largest oil and gas producer, PetroChina, on Thursday reported a drop of 78 percent in 2016 annual net profit, to its lowest since at least 2011, hit by lower prices for crude oil and natural gas.
The shrinking profits posted by China's state oil and gas producers for last year have highlighted their growing challenges from falling output from aging wells and excess supply in domestic fuel oil markets.
PetroChina's net profit sank to 7.86 billion yuan ($1.14 billion) from 35.7 billion yuan in 2015 as revenue fell 6.3 percent to 1.62 trillion yuan ($235 billion), based on IFRS accounting standards.
PetroChina's crude oil production fell 5.3 percent to 920.7 million barrels in 2016, after peaking at 972 million barrels in 2015, the company said in an earnings statement.
($1 = 6.8895 Chinese yuan)
Reporting by Josephine Mason and Meng Meng; Editing by Tom Hogue