LONDON - Aluminium prices stumbled to their lowest in 16 months on Thursday while other based metals also slid on renewed worries about weak demand after downbeat factory and property data in top metals consumer China.

Benchmark aluminium on the London Metal Exchange (LME) fell 2.5% to $2,300.50 a tonne in official open-outcry trading, its weakest since April 2021. A private sector survey showed China's factory activity contracted for the first time in three months in August while nearly 70 Chinese cities reported declines in new home prices, the most since the start of the COVID-19 pandemic.

"Industrial metals are taking a beating. The growth angst is most certainly having a profound impact across markets and reducing risk appetite once again," said Ole Hansen, head of commodity strategy at Saxo Bank in Copenhagen.

Factory activity was weak globally, surveys showed, while Hansen said that an expected increase to interest rates next week by the European Central Bank also weighed on markets.

"The supply side in metals could still be equally challenged, but right now the focus is on the risk to demand from central bank actions," Hansen said.

He added that investors were bailing out of some of their bullish positions in energy-intensive metals aluminium and zinc, which many analysts had expected to outperform because of production cutbacks in the face of high power prices.

LME tin tumbled 5.2% in official activity to a 19-month low of $21,600 a tonne after falling as much as 9%.

"Tin prices lost support following a production ramp-up in August and persistently weak demand in major end-user sectors like electronics," one China-based trader said.

"High overseas inventory and an open arbitrage window could mean rising supply in the Chinese market later this month."

Tin prices recovered slightly after news that Indonesia's biggest tin miner PT Timah said output slid 26% in the first half of the year.

LME copper shed 1.8% to $7,663 a tonne, zinc slumped 6.5% to $3,233.50, lead was down 1.7% at $1,916 and nickel dropped 3.9% to $20,575.

(Reporting by Eric Onstad, Additional reporting by Siyi Liu and Dominique Patton in Beijing, Editing by David Goodman)