New York corporate heavyweight Wachtell Lipton Rosen & Katz has been drafted in to advise on aluminium company Alcoa's split into two publicly traded companies.

Alcoa will split into an upstream company, made up of its bauxite, alumina, aluminium, casting and energy segments, and a downstream company that will include its global rolled products, engineered products, transportation and construction business divisions.

In 2014 Alcoa reported sales of $23.9bn (