Copper prices rose on Friday and were on track for their biggest weekly growth since late July after data from top metals consumer China showed signs of a stabilising economy.

Three-month copper on the London Metal Exchange (LME) was up 0.1% at $8,425 per metric ton in open-outcry trading after touching its highest since Sept. 4 at $8,507.50.

China's factory output and retail sales grew at a faster pace in August, though tumbling investment in the crisis-hit property sector threatens to undercut a flurry of support measures.

"The figures are likely to have a net positive effect on base metals prices given that they should further allay fears that the momentum of growth in China, the largest consumer, could continue to slow," Commerzbank analyst Thu Lan Nguyen said in a note.

"That said, no pronounced price rally can be expected until the real estate market shows clearer signs of recovering."

The economic data helped the yuan to strengthen against its U.S. counterpart, making dollar-priced metals more attractive for Chinese buyers.

The dollar was slightly weaker after hitting its six-month high on Thursday.

In the US, the United Auto Workers union began simultaneous strikes at three factories owned by General Motors, Ford and Chrysler-owner Stellantis, kicking off the most ambitious U.S. industrial labour action in decades.

Copper inventories in warehouses monitored by the Shanghai Futures Exchange have been rising for a month and this week reached their highest since late July.

Copper stocks in LME-registered warehouses are at their highest since October 2022 after sharp growth over the July-September period.

The discount for near-term delivery versus the LME three-month copper contract rose, indicating plentiful immediate supply. It closed at a one-month highof $45.25 a ton on Thursday, compared with $4.50 on Sept. 5.

LME aluminium dropped 1.3% to $2,196 a ton after China's monthly production reached record high in August. Tin slipped 1% to $25,625, zinc dropped 0.4% to $2,561, lead was unchanged at $2,245 and nickel lost 1.7% to $20,000.

(Reporting by Julian Luk in London Editing by Shilpi Majumdar and David Goodman )