Glencore Xstrata shares were performing well on Monday on speculation that the commodities trader and mining group is close to a multi-billion pound deal to sell its Las Lambas copper mine in Peru.According to The Wall Street Journal, Glencore Xstrata and Chinese state-controlled copper firm China Minmetals Corp are hoping to sign an agreement at a final meeting on Tuesday.The proposed disposal of Las Bambas, expected to be valued at around $5bn, was agreed by Glencore at the time of its merger with Xstrata in May 2013 in an effort to win approval from Chinese regulators.Alongside its 2013 results reported on March 4th, the company said that the sale process was still "ongoing".Speaking at the time, analysts at Jefferies said: "We expect at least a portion of what should be circa $5bn of proceeds from a Las Bambas sale to be returned to shareholders via a special dividend."The stock was 3.1% higher at 306.1p by 15:19.BC