By 2035, the top Chinese energy company aims to supply more zero-carbon products than the fossil fuels it consumes, putting it on course to reach its carbon-neutral target by 2050, Chairman Dai Houliang told a virtual earnings call.

Spending on greener products including wind, solar, geothermal and hydrogen power will expand "significantly year on year," Dai said, without giving detail.

He said the next five-to-10 years would be "the window for energy transitions" and the company was working on precise timelines.

In the near term, the company will focus on natural gas to cut emissions as China turns increasingly to the fuel to replace coal, an approach shared by domestic peers Sinopec Corp and CNOOC Ltd.

PetroChina aims to produce between 150 billion and 160 billion cubic metres of natural gas in 2025, which would be 21%-29% higher than last year.

PetroChina earlier reported a 58% fall in net income last year to 19.01 billion yuan ($2.91 billion), the lowest in four years, following falls in oil and gas prices linked to COVID-19.

Its crude oil output gained 1.4% last year to about 2.53 million barrels per day, while its gas production rose 8% to 4,221 billion cubic feet.

PetroChina, China's second-largest refiner, recorded an 11% fall in sales of transportation fuels last year as it faced fierce competition from private refiners in an over-supplied domestic fuel market.

But lower oil-linked import costs enabled the company to narrow losses incurred at its natural gas import business to 14.16 billion yuan, 16.55 billion yuan less than in 2019.

Its domestic natural gas business expanded further, especially in unlocking shale gas reserves in the southwestern Sichuan basin, as PetroChina overtook domestic rival Sinopec Corp in unconventional fuel production.

($1 = 6.5370 Chinese yuan renminbi)

(Reporting by Chen Aizhu; editing by Jason Neely and Barbara Lewis)

By Chen Aizhu