Randgold Resources Ltd.'s profit attributable to shareholders surged to US$84.0 million, or 88 U.S. cents per share, in the second quarter, from a profit of US$49.0 million, or 52 cents apiece, a year ago on the back of higher gold sales.

The company's gold sales swelled to US$422.1 million in the three months, from US$354.4 million, on sales of 336,516 ounces, from 280,519 ounces in the year ago period, according to the Aug. 3 earnings release.

Average gold price received for the quarter slid slightly to US$1,254 per ounce, from US$1,264 per ounce in the second quarter of 2016.

Revenues rose to US$336.8 million during the quarter, from US$276.8 million in the year ago period.

Randgold cut its total cash costs to US$192.4 million, from US$203.8 million in the year-ago quarter, as per ounce cash costs dropped 21% year over year.

Gold production in the three months surged to 341,316 ounces, from 281,494 ounces produced in the prior-year quarter.

Exploration and corporate expenditure was in line with the year-ago quarter at US$12.8 million.

In the first half of the year, Randgold's profit attributable to shareholders jumped to US$153.8 million, from US$105.0 million a year ago.

Gold sales in the six months swelled to US$831.7 million, from US$700.2 million in the prior-year quarter.

The company sold 672,119 ounces at US$1,237 per ounce in the half, up from 571,904 ounces sold at US$1,224 per ounce a year ago.

"At this stage the outlook is positive, and Randgold is trending towards the top end of its 2017 production guidance range at a total cash cost below $600 per ounce," CEO Mark Bristow said.