South African operation disruptions, production curtailments and a Chief Executive Officer (CEO) exit all add to near-term risks for Anglo American, according to Nomura which has slashed its estates for the mining group.The broker said that the stage is set for fourth-quarter production disappointments given the recent labour unrest and output curtailments elsewhere. "We have cut our near-term earnings forecasts by ~20% on average and now sit ~7% below consensus on average on the back of lower iron ore price forecasts and lower production. Looking forward, Q4 is likely to yield further production disappointments," Nomura said.The broker has also reduced its iron ore price forecasts for 2013 and 2014 to $125/tonne and $115/tonne, respectively. "These changes to our iron ore price forecasts account for roughly half of our 2013/14 earnings downgrades."Nomura has also cut its steel demand growth forecasts from around 3% to 2% for next year.Its price target for Anglo American has been reduced from 2,100p to 2,000p, accordingly.Meanwhile, last week's announcement that CEO Cynthis Carroll has resigned "also adds to the near-term uncertainty for the group," Nomura said."This management vacuum will naturally create a strategic/directional vacuum as well for the group. With strikes in South Africa and continued delays at its flagship iron project Minas Rio, this lack of direction poses presents further near-term risks."A 'neutral' rating for the stock has been retained.