Officials at global commodities giant and metals producer Glencore Xstrata Plc have announced 2013 profits increasing 20% amid copper output increases and falling costs.

Adjusted net income rose to $3.67 billion, from $3.06 billion year-on-year, according to representatives of the Baar, Switzerland-based company. It reported a 23% drop in pro-forma adjusted net income of $4.58 billion, exceeding a $4.01 billion guidance.

Glencore completed its Q2 2013 $29 billion takeover of Xstrata Plc last year to add coal, copper, zinc and nickel assets to its portfolio. The deal is forecast generate savings of up to $2.4 billion in 2014, Glencore anncounced this week, $4 million more over a $2 billion Q3 2013 estimate.

“We continue to see healthy growth in all our key commodities, underpinned by the long-term urbanization in emerging markets and parts of the developed world returning to trend growth,” said CEO Ivan Glasenberg in a statement quoted by Bloomberg News.

Overall copper production grew 26% to 1.5 million metric tons (Mt) in 2013, according to officials, with gains in Africa and Chile. Higher output and improved “cost management” mitigated weaker commodity demands, they added.

The world’s biggest exporter of power-station coal, meanwhile, wrote down asset values acquired in the Xstrata takeover by $7.7 billion in Q3 2013 reflect “the broader negative mining-industry environment.” Glencore also reported a full-year net loss of $7.4 billion on the writedowns.