China's Minmetals has submitted a first-round bid for Glencore-Xstrata's US$5.9 billion Las Bambas copper mine in Peru, said Gu Liangmin, the managing director of the state-owned metals and mining company. "We have come to the first round of bids for Las Bambas. I can assure that Minmetals is very realistic and all our actions should be rational and not too aggressive," Gu said at a conference in London. "We will be very cautious about our decision. It's unnecessary for Minmetals to buy assets at a crazy price or a price that we believe is not worth it." Glencore-Xstrata agreed to sell Las Bambas this year to meet demands from China's antitrust authorities after Glencore's takeover of mining group Xstrata. The regulator feared the tie-up handed the newly formed commodities powerhouse too much clout in copper. Glencore has long reported strong Chinese interest in Las Bambas, but there have been questions among analysts and observers over whether Beijing would allow competition between Chinese industrial groups or pick a horse to back. The mining company said last month that Chinese suitors might be allowed to compete against each other in the race for the mine, given strong interest. Chinalco Mining and Jiangxi Copper were among the Chinese groups also interested in the project, sources familiar with the bid said. One of the sources said Jiangxi Copper, the country's largest producer of the metal, had paired up with Chinalco. Peru's Mines Minister Jorge Merino said on Thursday that firms from several countries had expressed interest.