Freshfields Bruckhaus Deringer and Sullivan & Cromwell are advising on this year's first mega IPO in Hong Kong – that of the city's biggest electricity distributor.

Power Asset Holdings, owned by Asia's richest man and Hong Kong tycoon Li Ka-Shing, is hoping to raise $3.6bn through a listing of its utility business HK Electric Investments, offering 4.43bn units for up to HK$6.30 per share.

The offering represents 50.1% of the business. According to reports the company was previously planning to float 70% in the hopes of raising $5.7bn from the listing, but revealed a lesser offering earlier this week.

US outfit Sullivan & Cromwell is representing the company on US law, with a team being led by Hong Kong-based corporate partner William Chua.

Advising on Hong Kong law is Woo Kwan Lee & Lo, whilst offshore firm Conyers Dill & Pearman is providing Cayman counsel.

Magic circle firm Freshfields is acting for the banks on the deal, which include Goldman Sachs and HSBC as joint global coordinators and joint bookrunners.

Hong Kong corporate partner Grace Huang is leading a team for Freshfields, acting as Hong Kong and US counsel.

The IPO will be the largest so far in 2014, and is understood to be the biggest IPO in the city since AIA's $20.1bn flotation in 2010.

It follows a more successful period for Hong Kong capital markets in the latter half of last year, which boosted the total amount raised during 2013 to HK$169bn, an 88% increase on 2012, according to PwC.

Related: CC and Latham advise on Hong Kong IPO of China's Huishang Bank