Xstrata has raised its copper mineral resource estimate at the major long-life development El Pachón project in San Juan Province, Argentina.

Total mineral resources have jumped by 20% to 3.3bn tonnes at a grade of 0.47% copper using a cut-off grade of 0.2% copper, and include additional silver and molybdenum by-product credits.

Total contained copper metal has increased by 16% to 15m tonnes.

Xstrata said that El Pachón has the potential to initially produce 400,000 tonnes of copper per annum.

The miner said on Wednesday morning: "The new estimate is the result of the remodelling of the deposit including additional drilling from prior drilling campaigns not previously accounted for and the use of new geotechnical, metallurgical and economic parameters developed as part of the project's final feasibility studies."

The company announced on Monday that it had reached agreement on the final terms of a revised recommended all-share merger of equals with commodities trader Glencore.

"The strategic rationale for the merger remains compelling and the transaction has the potential to create superior value for Xstrata Shareholders," the firm announced.

Shares were broadly flat in early trading on Wednesday.

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