Company newsOyu Tolgoi's massive copper-gold-silver complex will reach commercial production by 2013, Rio Tinto (LSE:RIO,ASX:RIO,NYSE:RIO) said Thursday in response to a media report stating that the company is considering a temporary halt in construction for political reasons. "The power is secured, first ore produced and the concentrator switched on," Rio Tinto spokesman Illtud Harri told Reuters. "We are on schedule for first commercial production in the first half of the year." Rio was allegedly considering halting the $6.2-billion project to protest Mongolia's demands for a larger stake in the project and new royalty rates, Bloomberg reported. The government of Kyrgyzstan is once again trying to force Centerra (TSX:CG) to renegotiate its mining license for its Kumtor open-pit mine, EurasiaNet reported on Monday. The former Soviet republic last year cancelled surface mining rights granted to the Canadian gold miner on accusations that the company is damaging the environment and stealing the country's wealth. The mine has produced 8.4 million ounces of gold since 1997 and accounts for 60 percent of the Central Asian republic's industrial output. Bloomberg reported that AngloGold Ashanti (NYSE:AU) expects to overshoot costs for its Tropicana mine by 13 percent. The company blamed an overheated Western Australian construction market, along with extreme skill shortages and higher labor costs, in explaining the new estimate of between AU$820 million and $845 million. In 2010, the mine's capex was estimated at $775 million. Junior company news On Monday, Atacama Pacific Gold (TSXV:ATM) released a preliminary economic assessment (PEA) for its Cerro Maricunga oxide-gold project in Chile. The PEA targets annual production of 298,000 ounces over the first five years of a 10-year mine life. The Toronto-based company said the project is "globally one of the largest oxide gold projects under consideration for development." Guyana Goldfields (TSX:GUY) filed a technical report relating to its Aurora gold project in Guyana. The report outlines an open-pit, underground operation that will yield 194,000 ounces per year over a 17-year life of mine, with 231,000 ounces produced on average in the first 10 years.