Freshfields Bruckhaus Deringer and Simpson Thacher & Bartlett are understood to have taken much-coveted roles on the Hong Kong initial public offering (IPO) of Alibaba, China's largest e-commerce company.

The listing, set to be the biggest IPO since Facebook, could reportedly value the company at as much as $100bn (£64bn), although more conservative estimates have pegged the value at between $60bn (£39bn) and $70bn ($46bn).

Magic circle firm Freshfields is understood to be advising Alibaba, with the firm's top Hong Kong IPO partner and Greater China head Teresa Ko leading a team.

US outfit Simpson Thacher, meanwhile, is thought to be representing the underwriting banks, with China practice leader and Hong Kong capital markets partner Leiming Chen heading up.

Although Alibaba has not yet formally named the banks on the deal, Reuters reported earlier this month that Credit Suisse is expected to take a lead role on the float, which could take place as early as the end of 2013.

Freshfields and Simpson Thacher have both previously represented Alibaba, with the magic circle firm recently advising on the firm's $8bn (£5.1bn) debt refinancing, as well as last year's $7.1bn (£4.5bn) buyback of a 20% stake in the company from Yahoo!.

Meanwhile, Simpson Thacher this year advised the Hangzhou-based business on its $586m (£378m) purchase of an 18% stake in Chinese social media company Weibo. Simpson Thacher also acted for the banks on Facebook's high-profile IPO last year, which valued the business at $104bn (£68bn).

A potential listing in Hong Kong would be a welcome development for Asia's financial capital, which last year saw a significant drop in the volume and value of listings, with 64 new IPOs valued at HK$89.8bn (£7.1bn) during the period, down from 101 priced at a total of HK$271.4bn (£21.6bn) in 2011.

Freshfields, Simpson Thacher and Alibaba declined to comment.