Clifford Chance (CC) and Hogan Lovells are advising on the high-profile initial public offering (IPO) of New York's iconic Empire State Building, which has this week received shareholder approval to proceed.

The IPO, which is expected to raise at least $1bn (£660m), has received backing from more than 80% of investors in Malkin Holdings, the owner of the Manhattan skyscraper.

Malkin, which took over the building in 2002, officially filed for the shares offering in February last year, but the IPO has to date faced resistance from some shareholders.

The vote will see the 102-storey landmark folded into a portfolio of New York properties in a newly created real estate investment trust, named The Empire State Realty Trust, which is reportedly valued at $4.2bn (£2.8bn), and will be traded on the New York Stock Exchange.

Filings with the US Securities and Exchange Commission (SEC) show that CC has been advising Malkin Holdings in the US with a team comprising New York capital markets partners Larry Medvinsky and Jason Myers, alongside Proskauer Rose capital markets partners Arnold Jacobs and corporate counsel Steven Fishman.

The SEC filing also states that Hogan Lovells has been handling legal matters for the underwriters, with Washington DC corporate partner Stuart Barr named as the lead partner. Bank of America Merrill Lynch and Goldman Sachs are the underwriters to the offering.

The role for CC represents a key mandate for the magic circle firm's US practice, which also last year took a major role for Brazilian airline Tam on its $14bn (£9bn) merger with Chilean rival Lan.