Clifford Chance and Simpson Thacher & Bartlett have been called in to act on Chinalco's mega US $21bn financing ahead of what is widely expected to be its US $19.5bn investment in mining giant Rio Tinto.

The financing was secured by way of a loan from a syndicate of banks led by the China Development Bank. Bruce Schulberg and Beijing and Shanghai managing partner Stephen Harder led the Clifford Chance team who acted for the lenders while PRC firm King & Wood advised the lenders on local law. 

A Simpson Thacher & Bartlett team led by Beijing-based Doug Markel and comprising of UK finance partner Euan Gorrie, NY-based Alan Klein and Washington-based Peter Thomas  acted for Chinalco while Chinese firm Commerce & Finance advised the company on local law.

Clifford Chance and Linklaters are acting for Chinalco and Rio Tinto respectively on the proposed acquisition which is still pending shareholder approval. If it does go ahead, the move will be the largest ever outbound investment by a Chinese company and see Chinalco increase its stake in Rio Tinto from 9% to 18%.