By Rhiannon Hoyle

CopperTech Metals delayed its U.S. initial public offering a day before it was to start trading, citing volatility in global markets.

The copper and cobalt company filed for an IPO in June and was expected to begin trading on the New York Stock Exchange on Wednesday. CopperTech, a U.S.-domiciled unit of billionaire Anil Agarwal's Vedanta Resources, was established to own and operate the Konkola Copper Mines in Zambia.

"Following careful consideration of current market conditions and recent volatility across the global copper equity sector, Vedanta and CopperTech have decided to postpone the proposed IPO," CopperTech said in an email.

The company had planned to raise more than $400 million and aimed for a valuation topping $3.5 billion. It said it wanted to capitalize on forecasts for strong copper demand related to the growth of artificial-intelligence infrastructure.

CopperTech said it remains "fully committed to creating long-term value for all stakeholders and will continue to evaluate the appropriate timing for the proposed IPO."

Write to Rhiannon Hoyle at rhiannon.hoyle@wsj.com