Slaughter and May, Bredin Prat and Freshfields Bruckhaus Deringer have taken lead advisory roles on proposed new joint venture agreements between PetroChina and chemicals producer Ineos.

Ineos instructed a team of lawyers from Slaughters and its French best friend firm Bredin Prat to advise on the venture that will see the Chinese energy giant partner with Ineos to trade and refine oil at refineries in Scotland and France.

Slaughters corporate partner Robert Stern led a team including corporate, finance, competition and employment lawyers from the magic circle firm. Bredin Prat fielded a team led by Olivier Rogivue.

Freshfields advised PetroChina from its Hong Kong and London offices. China managing partner Teresa Ko led the Hong Kong-based team, while corporate partner Julian Long led in London.

The joint venture framework, which was announced this week (10 January), is set to see the two companies form a new partnership to refine and trade oil at Scotland's Grangemouth and France's Lavera refineries, and will give PetroChina access to Europe's refining markets.

Ineos and PetroChina's parent company China National Petroleum Corporation have also signed a separate agreement to share refining and petrochemical technology and expertise.

The signing of both agreements was witnessed by Deputy Prime Minister Nick Clegg and Chinese vice premier Li Ke Qiang.

Slaughters has a longstanding relationship with Ineos and has advised on a number of large-scale deals for the company, including its $9bn (£5.7bn) acquisition of petrochemicals business Innovene from BP in 2005.