Gold Fields Ltd., the fourth-biggest producer of the metal, said Ghana’s plan to raise tariffs on mines and introduce a windfall tax could force it to halt expansion projects worth $1 billion in the country.

Suncor Energy Inc. Chief Executive Officer Rick George will retire next year after leading the oil- sands producer for more than two decades and transforming it into Canada's largest energy company.

Workers at the Collahuasi copper mine, a joint venture between Anglo American Plc and Xstrata Plc in northern Chile, agreed today to end a strike over job dismissals after winning concessions from their employers.

Bloomberg reports Graff Diamonds, the producer and retailer whose founder twice set records buying gems at auction, plans to raise about $1 billion in an initial public offering in Hong Kong, according to a person with knowledge of the matter. Graff follows other luxury product makers such as Prada to Hong Kong as China surpasses Japan to become the second-biggest buyer of diamonds behind the US, where demand rose 7 percent last year, compared with 25 percent in the communist country, according to De Beers.

Julia Gillard, determined to join efforts to reduce global warming, intends to revive cap and trade as Europe puts curbs on the United Nations-run emissions credit market and the U.S. opts out entirely. The Australian prime minister’s plan to make factories and utilities either cut the nation’s greenhouse gases or pay for pollution-curbing programs abroad may force companies to buy an average 66 million metric tons of credits a year starting in 2015, sending prices up 29 percent, according to Bloomberg New Energy Finance. That’s about two-thirds of Europe’s annual demand since 2008.

Rio Tinto Group and Anglo American Plc (AAL), which together own about three-quarters of Palabora Mining Co., said they plan to sell their entire holdings in the South African miner as it no longer fits their investment objectives. Palabora’s main asset, a mine that produces copper and magnetite, “is no longer of a sufficient scale” for either Rio or Anglo, and a sale process for their stakes has started, the companies said today. Rio holds about 58 percent of Palabora and London-based Anglo almost 17 percent. Their combined holding is valued at about $700 million based on the closing price of Palabora stock in Johannesburg trading today. Image of copper spools at Palabora mine, courtesy of Rio Tinto

Rio Tinto Group said it received partial approval from the Zimbabwean government for its plan to increase ownership of the Murowa diamond mine by black citizens of the country.

AuRico Gold Inc. is paying the cheapest valuation for a takeover of a North American gold producer in seven years even as bullion trades at a record. Including net cash, AuRico’s acquisition valued Northgate at 14.7 times Ebitda. In last year’s biggest North American gold takeover, Toronto-based Kinross, Canada’s third-largest producer of the metal, paid 40.4 times Ebitda to acquire Red Back Mining of Vancouver in a $6.7 billion deal.

Bloomberg reports demand for diamond jewelry in India may slow as a surge in prices discourages buyers. Polished diamond prices, which jumped about 60 percent to 70 percent in the last six months, may gain further in the next few months, said Sandeep Kulhalli, vice president, retail and marketing at Tanishq, the jewelry retail chain owned by Titan. The company is India’s biggest retailer of gold jewelry.

Copper rose the most in more than two weeks on speculation that a strike at the world’s biggest mine may worsen a global supply shortage. A strike at BHP Billiton Ltd.’s Escondida mine entered a fifth day as Chilean labor authorities prepared to mediate talks between union and company officials.

Bloomberg reports nickel is the only base metal traded on the LME to record a decline in its inventories this year. Refined nickel usage exceeded output by 24,000 metric tons in the first half, according to estimates by Barclays Capital.

Australia’s planned carbon tax may reduce the value of the coal industry by about $8.7 billion as producers including Xstrata Plc and Anglo American Plc bear higher costs, according to a research group Wood Mackenzie Ltd. Prime Minister Julia Gillard plans to charge companies an initial A$23 a ton of carbon dioxide from July 2012 before moving to an emissions trading system by 2015. Coal mining companies in Australia, the world’s largest exporter, must pay for fugitive emissions while receiving A$1.3 billion in compensation, with the biggest polluters getting assistance over six years.