JOHANNESBURG, July 31 (Reuters) - A proposed tour of European capitals by African mining ministers to protest against central bank gold sales has been cancelled.

South African Minerals and Energy Minister Phumzile Mlambo-Ngcuka said African mining ministers had adequately voiced their concerns at meeting of 71-developing countries in Brussels last week.

The two-day meeting of African, Caribbean and Pacific (ACP) ministers issued a statement on Wednesday calling for a moratorium on central bank gold sales pending study of a ``central mechanism'' to permit orderly gold sales.

``We were able to discuss all the issues which we would have taken on a (European) tour. It would be overkill,'' Mlambo-Ngcuka told Reuters late Friday after visiting the Mponeng mine near Johannesburg where a gas explosion killed 19 miners late Thursday.

South Africa had originally planned a mission to London and other European capitals after Britain's first auction of gold reserves on July 6 sent bullion prices tumbling to 20-year lows.

But the tour was postponed while South Africa gathered support from other African gold producing countries like Ghana, Mali and Tanzania.

In the interim, a separate delegation of South African gold executives and union leaders had travelled to London to plead the industry's case. But they failed to shift the British government's thinking on its plan to cut its gold reserves by 415 tonnes over the next few years.

South Africa's gold mines are struggling to cut costs in the face of weak gold prices, which if they persist, could threaten 100,000 direct and indirect mining jobs.

Aside from the UK sales, proposed gold sales by Switzerland and the International Monetary Fund (IMF) have also raised fears among gold producers of a further drop in bullion prices.

The ACP statement urged ``that a moratorium be placed on all official sector gold sales until a representative forum is speedily established to explore a central mechanism that can be put in place to ensure that gold sales take place in a structured and orderly manner...''

Mlambo-Ngcuka said the ACP declaration had given European Union (EU) officials at the meeting ``food for thought.''

``There is willingness to find a mechanism to continue to discuss this. At an EU level, the issue has been noted,'' she said.