Copper prices were heading for the first weekly gain in six weeks in London on Friday supported by worries that a strike at a major mine in Chile could tighten supply.

Three-month copper on the London Metal Exchange fell 0.8% to $9,072 per metric ton by 1037 GMT after hitting a two-week high of $9,184.50 earlier in the session. The metal, used in power and construction, is up 2.3% so far this week.

A strike at mining giant BHP's Escondida mine in Chile, the world's largest copper mine that accounted for nearly 5% of global supply in 2023, sparked concerns about supply disruptions.

"This should offset any concerns over weaker demand in coming months," analysts at ANZ said. A 44-day strike in 2017 at Escondida sparked a copper price rally. There were also other strikes in 2006, 2011 and 2015.

Meanwhile, the effect from the risk of supply disruptions has been muted by continuing growth in copper stocks in the LME-registered warehouses , which almost tripled over the last three months.

They rose by 1,600 tons to 309,050 tons, the highest in almost five years, daily LME data showed on Friday. Copper inventories in warehouses monitored by the Shanghai Futures Exchange (SHFE) fell 8.4% this week.

Meanwhile, positive U.S. retail sales and jobs data eased worries about a potential recession in the country that had pushed base metals prices down in the past three weeks.

On the technical front, copper is supported by the 200-day moving average at $9,060.

LME aluminium shed 0.9% to $2,342 a ton, tin lost 0.8% to $31,670, zinc dipped 1.1% to $2,750.50, lead edged down 1.1% to $2,011 and nickel declined 1.0% to $16,140.

(Reporting by Polina Devitt in London; additional reporting by Mai Nguyen in Hanoi; Editing by Emelia Sithole-Matarise)