Allen & Overy (A&O) is set for a headline role on Manchester United's planned $1bn (£640m) Singapore initial public offering (IPO).

The magic circle firm is understood to be advising longstanding client Man Utd on the listing, with global corporate co-head and relationship partner Andrew Ballheimer leading the firm's team.

A&O regularly advises Man Utd on corporate finance matters, and acted for the club's current owners, the Glazer family, on their 2004 takeover, as well as the club's £500m bond issue in January 2010, which saw the firm field a team led by high yield partner Kevin Muzilla.

Meanwhile, Herbert Smith is believed to be advising the underwriters on the listing. The IPO is reportedly being managed by Credit Suisse, JPMorgan Chase and Morgan Stanley, alongside a number of Asian banks.

Herbert Smith last year took a lead role on the largest IPO in history, advising the underwriting banks on the $22bn (£14bn) Hong Kong and Shanghai dual listing of Agricultural Bank of China.

The Man Utd IPO, first touted for mid-October, is reported to have been pushed back because of market volatility, with the Premiership club still hoping to complete the listing by the end of the year.

The listing has been closely watched due to the intense competition among international law firms for lucrative Asia capital markets work. The IPO is also notable due to Man Utd's choice to turn to Asia, reportedly the home of around two thirds of its 300 million global fanbase.

The Financial Times and Reuters have both reported that the club is expected to sell around a third of its total equity – valued at $3bn (£1.9bn) – through the listing.

Man Utd reviewed its panel of legal advisers last year, with Pinsent Masons winning a second term alongside Brabners Chaffe Street. Pinsents advises the club on data protection and employment, while Brabners handles dispute resolution and real estate work as well as some aspects of commercial law.

A&O and Herbert Smith declined to comment.