Miner Kaz Minerals' shares rose as copper production more than doubled in the first quarter from the previous year.
In a trading statement for the three months to the end of March, the Kazakhstan-focused company ramped up production, increasing copper output to 52,000 tonnes from 22,700 tonnes the previous year, or up 16 per cent from the previous quarter.
Gold production increased to 42,500 ounces from 17,700 ounces the previous year and silver lifted to 757,000 ounces from 706,000 ounces in 2016.
Net debt stood at $2.55bn (£1.98bn) at 31 March.
The FTSE 250 company's shares lifted nearly five per cent this morning, making it the top FTSE midcap gainer. Its stock was up 2.48 per cent at 491p at the time of publishing.
Why it's interesting
Kaz's Aktogay mine benefited from high grade copper and a contribution of 7,000 tonnes of copper from its sulphide concentrator, which started production in mid-February. The company said it is on-track to meet its full-year 2017 copper production guidance of 225,000 to 260,000 tonnes.
It added 2017 project expenditure guidance for its Aktogay mine has been reduced.
Yuen Low, analyst at Shore Capital, said: "From our point of view, every little saving could prove very helpful.
"In February 2017, we noted that Kaz’s balance sheet posed something of a concern. Within the next few months, Kaz has to persuade its lending banks to agree a refinancing of the PXF facility with a view to amending financial covenants to ensure a breach is not triggered, and to increase available liquidity by extending the facility amount and duration."
Kaz also announced chief executive Oleg Novachuk will step down and take on the role of chair from 1 January 2018 after 11 years at the helm of the company. Andrew Southam, chief financial officer, will become the boss of the firm.
What Kaz Minerals said
Chief executive Oleg Novachuk said: "I am pleased to report continued progress in the ramp up of our new mines, including an excellent first quarter of production from sulphide operations at Aktogay.
"Kaz Minerals is delivering industry-leading production growth as promised to the market and was amongst the lowest cost copper producers globally in 2016."