BEIJING (Reuters) - China’s annual aluminum production fell for the first time in 10 years in 2019, official data showed on Friday, hit by softer demand amid the Sino-U.S. trade row and large-scale smelter outages.

Aluminum output dropped to 35.04 million tonnes last year, down 0.9% from record levels a year earlier, the National Bureau of Statistics (NBS) reported.

China’s full-year aluminum output last fell in 2009, according to annual data on the NBS website, although estimates from the International Aluminum Institute show production rising every year this century.

The drop in annual output came as major smelters suffered unplanned outages from August. Top producer China Hongqiao Group 1378.HK closed some lines because of flooding in Shandong province and Xinfa Group had an explosion at a site in Xinjiang.

But it also highlights the impact of China’s economic slowdown on the sector, ending a decade of break-neck expansion that saw China increase its dominance of global aluminum production and consumption.

China’s annual aluminum consumption was set to fall for the first time in 30 years in 2019, research house Antaike said in November.

December aluminum output came in at 3.04 million tonnes, the NBS said, up 4.9% from the previous month thanks to a wave of restarts at smelters. It was down 0.7% from the all-time high hit in December 2018 but still the second-highest monthly figure on record.

Output averaged about 98,000 tonnes per day last month, according to Reuters calculations, up from around 96,600 tonnes per day in November.

Almost 1 million tonnes of annual aluminum smelting capacity restarted in December, mostly in western regions such as Qinghai and Xinjiang, said Lu Chen, a Beijing-based analyst for CM Group.

The restarts were due to a combination of higher prices and completed repairs, said Lu, who expects January output to rise following the start-up of Henan Shenhuo’s new plant in Yunnan on Dec. 31 and the second phase of Yunnan Aluminum’s Heqing smelter earlier this month.

Lu forecasts China will bring a total of 2 million tonnes of additional capacity on line in 2020.

Output of 10 nonferrous metals - including copper, aluminum, lead, zinc and nickel - came in at 5.31 million tonnes in December. That beat the previous monthly record of 5.11 million tonnes in November and was up 4.7% year-on-year.

Total 2019 output for this group of metals, which also includes tin, antimony, mercury, magnesium and titanium, rose 3.5% year-on-year to a new annual record of 58.42 million tonnes.