Since news spread of Rio Tinto's latest A$30bn deal with Chinalco, ALB has confirmed that Mallesons Stephen Jaques' Peter Cook (pictured) is acting for the Chinese state-owned steel maker.

The proposed deal includes the sale of US$12.3bn of Rio's assets, including 15% of the Pilbara-based Hamersley Iron operations, 29% to 50% of the Weipa, Yarwun and Boyne aluminium operations and 21% of the Gladstone power station. Chinalco will pay $US7.2bn for convertible bonds which, once converted to shares, would increase its stake in Rio from 9.3% to 18%.

However, the transaction may face greater regulatory hurdles as, minutes before it was confirmed, Australian treasurer Wayne Swan announced that he would seek parliamentary approval to amend the Foreign Acquisitions and Takeovers Act.

One of the notable changes is that any investment - particularly those involving instruments such as convertible notes - would be treated as equity. Swan said that while the federal government welcomed investment, foreign investments in the mining sector must be in the "national interest".

Cook previously acted on Chinalco's 9.3% stake acquisition in Rio Tinto, along with Clifford Chance, Simpson Thacher and Sullivan & Cromwell.