Despite attempts by the government to get more revenue from the sector through tax, multinational mining companies are still keen on mineral-rich Ghana's prospects.

Ghana's government may have raised its royalty tax to a flat five percent in 2012, hiked corporate tax from 25 percent to 35 percent and continued to mull over a 10 percent windfall profits tax, but mining companies remain bullish about their prospects in the country.

"We face these pressures for increased resource nationalism all over the world. So Ghana's new taxes are not exceptional," said Richard Duffy, AngloGold Ashanti's executive vice-president for continental Africa, told journalists at the Mining Indaba in Cape Town in early February.

"When we merged with Ashanti in 2004, we paid a combination of cash and shares to achieve certain fiscal terms. In effect, we compensated the government in advance. We are now engaging with the government about this agreement and how it can be respected going forward," explained Duffy.

However, the government is reviewing stabilisation agreements that protect AngloGold and Newmont from tax changes. Labour unrest in South Africa caused companies to examine the profitability of their operations there.

Last year South Africa's Gold Fields, which operates Ghana's Tarkwa mine, announced its intention to split off its ailing South Africa operations into a new company called Sibanye Gold.

Tarkwa remains a bright spot, with the mine reporting an 11 percent increase in quarter-on-quarter production for the last three months of 2012.

"The main thing for us is that Ghana is stable. The windfall tax is troubling, but everything else about Ghana, from a global perspective, is favourable," said Darren Lindsay, chief executive of Castle Peak Mining, a junior exploration company.

Michael Bosman, director of transaction advisory services in the Johannesburg office of Ernst & Young, points to security of tenure for investors, political stability and new oil wealth as factors for optimism. However, he says Ghana's government has a major headache with its low rate of corporate tax compliance.

"The big companies have historically negotiated their tax rates with the government. Now the government is under pressure to borrow less on local markets, and to do this, there is a general move to boost tax revenues and ensure compliance," said Bosman.

Ghana's gold exports during the first half of 2012 earned $3.2bn, up 32 percent on the same period in 2011, according to the Bank of Ghana.