Gold output dropped 25% year-on-year to 92,803 ounces in the June quarter, bringing the total for the first half of the year to 217,099oz, 7% less than the same time last year. 

Centamin mined 5.5 million tonnes of openpit ore, up 81% on the year, at an average grade of 0.51g/t, down 33%, and 289,000 tonnes of underground ore, up 2%, at an average mined grade of 4.62g/t, down from 8.79g/t a year ago.

Centamin attributed the lower underground grades to greater-than-scheduled dilution from low-grade porphyry material cutting stope grades and focus on access drives to future mining areas hitting development grades.

The company said development at its Cleopatra exploration and development project had ramped up during the June quarter, with the second crew and equipment being mobilised to the site in late April.

It said it had completed 7,169m in exploration drilling, with development of 540m delivering 47,692 mined tonnes at an average development grade of 1.77g/t.

The market wasn't pleased with the results, with Centamin shares dropping 7.3% Monday to £1.09 (US$1.47) per share.