Gold producer says its total gold output from mines fell to 522,917 oz in the quarter ended Sept. 30 from 615,498 oz in the same period a year earlier.
Shareholders argue Barrick decision to hand Tanzania 50 percent of "economic benefits" from Acacia's mines may set baseline for future host nations' demands.
Petra Diamonds Ltd's first quarter revenue fell by 17 percent after Tanzanian government last month seized consignment of diamonds from its Williamson mine.
Chief Financial Officer Andrew Wray said the company doesn't even have the ability to make the upfront $300 million payment Barrick has promised to the government of Tanzania as part of a deal reached Thursday.
It will sell its newest mine to Harmony Gold for $300 million and another mine for 100 million rand ($7.4 million) to China's Heaven-Sent SA Sunshine Investment Company.