Adjusted underlying earnings (EBITDA) fell to $91.6mln in the six months through June from US$166.2mln the same period a year ago.
Revenue dropped 15% to US$333.4mln from US$391.6mln last year.
Production continues to slide
Production decreased 41% to 254,759 ounces from 428,203 ounces and gold sales were broadly in line with output.
The company scaled back operations at it two of its three mines in Tanzania - Bulyanhulu and Buzwagi – after the government banned it from exporting gold and copper concentrates.
Acacia’s majority owner Barrick Gold has been negotiating with the Tanzanian government to lift the ban.
Since the ban does not apply to gold doré bars, the miner expects this to account for all of its gold production in 2018.
RBC Capital Markets said while the results are likely to disappoint the market today it notes that first half EBITDA sits at 50% of the full year consensus forecast and 52% of its own estimate for the year.
It added: "With uncertainty in Tanzania high and no visibility on when or what type of outcome there may be we reiterate our sector perform, speculative risk rating."
Acacia generates free cash flow for the first time since 2016
Despite the declines in earnings, revenues and production, Acacia said it generated free cash flow of US$14mln in the second quarter for the first time since 2016.
“The changes we made to the business in late 2017 have delivered the desired results, helping to return the group to free cash generation for the first time since the fourth quarter of 2016 and we are on track to achieve the top end of our production guidance range of 435,000-475,000 ounces for 2018 at an AISC of US$935-985 per ounce,” said interim chief executive Peter Geleta.
“Following the stability we have brought to the business during the last six months, our priority remains on optimising performance across all areas of our operations as we manage through the current uncertainty in the operating environment and the on-going disputes with the Government of Tanzania.
“By continuing to be resilient, managing our costs and working to our mine plans, we are addressing what we can control and will look to deliver value for all of our stakeholders.”
Shares fell 4.8% to 111p each.
Liberum said cashflow was flattered by US$45mln of proceeds from the disposal of its 2% net smelter royalty in the Hounde gold mine in West Africa a ndwithout which the cash pile would actually have fallen.