Of direct relevance to nickel investors, another research firm, UBS, said now could be a good time to pick up undervalued coal and nickel stocks whose prices are trading "close to spot and marginal costs." As reported by Reuters: "[t]he research house's top picks included state-owned coal miner PT Bukit Asam (OTC Pink:TBNGY) and nickel producer Vale Indonesia (OTC Pink:PTNDY) as they are high-volume growth miners with sector-low cost bases."Cuban nickel plant closes Steel Guru reported that Cuba has closed the oldest of three nickel plants in the country. The news outlet quotes a communist party official in Eastern Holguin, the location of the plant, as saying that, "[t]his plant's productive role is completed and now it will dedicate its efforts to services." Nickel is Cuba's most important export and is a top earner of foreign exchange. Steel Guru reported that the island nation produced 69,700 tonnes of raw nickel plus cobalt in 2010. Canada-based Sherritt (TSX:S)produced 34,572 tonnes of nickel and 3,854 tonnes of cobalt in 2011 through the Moa joint venture, a nickel-cobalt mining operation owned by subsidiaries of Sherritt and Cuban company General Nickel Company (GNC). Company news First Quantum Minerals (TSX:FM) announced in the middle of December that it is moving forward with its third nickel mine, Enterprise, as part of an $840-million expansion plan in Zambia. The Toronto-based company said it expects Enterprise to be a low-cost producing mine given synergies with its Sentinel copper mine. "The 4.0 Mtpa processing plant that will be built at the Sentinel facilities will consist of straight forward crushing, milling and flotation. The plant will be designed with the flexibility so that if nickel ore from the Enterprise is not being processed, it can be used to augment the Sentinel copper throughput capacity by approximately 4 Mtpa," First Quantum said in a statement.