Clifford Chance is advising Royal Dutch Shell Plc. on a $5.7 billion divestment of most of its interest in Australian oil and gas company Woodside Petroleum Ltd.

Shell is reducing its stake in Woodside from 21.3 percent to 4.5 percent. In a statement, Shell said that it wanted to focus its on directly owned assets in Australia.

The oil giant is planning to sell half the shares it is offloading to institutional investors. Woodside has agreed to buy back the other half, subject to shareholder approval.

Clifford Chance Sydney partner Lance Sacks is acting for Shell, with help from Hong Kong partner Crawford Brickley.

Herbert Smith Freehills Sydney partner Philippa Stone and Perth partner David Gray are representing Woodside.