Mines Permanent Secretary Paul Chanda attributed the decline to challenges such as declining ore grades but said full-year output is likely to exceed 2018 figures.

"Our estimates still indicate that we are likely to exceed last year's production of slightly over 861,000 tonnes and reach close to 900,000 tonnes this year," Chanda told Reuters.

Production for the first six months of 2019 fell to 393,419 tonnes from 410,919 tonnes in the same period last year.

Zambia’s Chamber of Mines said in May that 2019 output in Africa's second-largest copper producer could be as much as 100,000 tonnes lower than last year because of changes to mining taxes.

The country's new finance minister on Wednesday said he would soon give a clear position on replacement of Zambia's value-added tax with a non-refundable sales tax. [nL8N24I26R]

Since being appointed this week Bwalya Ng'andu has sought to mend fences with Zambia's mining industry. The proposed tax is a sore point between the government and mining companies. [nL8N24G0FK]

(Reporting by Chris Mfula; Editing by David Goodman)