Gold miner Centamin has warned investors that its Stage 4 expansion project has experienced some delays for key items, materials and services.Partly as a result of the delay, as well as general cost inflation, the group now estimates the total capital cost of Stage 4 will be $325m, including contingency, as compared with the previous $287.6m, excluding contingency.The group said: "We now anticipates the bulk of commissioning activities of the expanded plant will commence during the second half of 2013, although there is no change to our expectation that the plant will be fully operational before the end of the year."In the same announcement, the company also revealed that the forecast production for the year 2013 from the Sukari Gold Mine is 320,000 ounces of gold, up 22 per cent on 2012 levels. The gold will be produced at a cash operating cost of $700 per ounce with fuel at international prices. If the predicted production levels are achieved, it will mark the third successive year of output growth at Sukari and will see the company move towards its long-term target of 450-500,000 ounces per annum from 2015 onwards.The share price fell 0.93% to 53p by 08:35 on Thursday. NR