Clifford Chance (CC) is acting alongside two Canadian firms on PetroChina's proposed $5.4bn (£3.4bn) investment in Canadian energy company Encana's natural gas assets, reports The Am Law Daily.

Oil giant PetroChina will take a 50% stake in Encana's Cutbank Ridge natural gas assets in British Columbia and Alberta, in a deal set to mark the largest-ever Chinese investment in Canada's energy sector.

A team from the CC's Hong Kong office is advising PetroChina on securities compliance issues, with corporate partner Amy Lo taking the lead role.

Toronto-based firm Osler Hoskin & Harcourt is representing PetroChina on the deal, fielding a team led by corporate partners Robert Desbarats and Paula Olexiuk in Calgary, alongside Calgary corporate partner Janice Buckingham and Toronto competition partner Peter Glossop.

Calgary-based Burnet Duckworth & Palmer is advising longstanding client Encana, with the firm's deal team led by corporate partners John Cuthbertson and Alicia Quesnel.

The deal is subject to regulatory approvals, including clearance under the Investment Canada Act, which governs overseas investment into the country.

Chinese acquisitions in Canada and the US increased by 81% in 2010, reaching $6.8bn ($4.3bn) by the end of September. The energy and resources sector alone accounts for 70% of the increase.

Additional reporting by Julie Triedman

The Am Law Daily is a US affiliate title of Legal Week.