The American owners of Manchester United pocketed around £75m as shares in the football club were publicly traded for the first time in seven years.

Some 16.6 million shares, equal to 10% of the club, were floated on the New York Stock Exchange to great fanfare as members of the Glazer family rang the opening bell.

The 134-year-old club offered shares for $14 (£9) a piece - giving United a market value of $1.5 billion - but there was little price movement in early trade.

The offering was substantially lower than the 16 to 20 US dollars originally proposed by its advisers - which would have valued the club at £2.1bn at the top end.

The flotation will raise around $150m with roughly half the proceeds going to the Glazers, who bought the club in 2005 for £800m, while the remaining proceeds will be used to pay down some of the Red Devils' $423m debt pile.

As trading started, United's co-chairmen Avram and Joel Glazer and chief executive David Gill applauded from the stock exchange's balcony, which was adorned with the club's emblem, while New York traders wore the club's trademark red home kit.

The lower flotation price comes after the Glazer family, which also owns the Tampa Bay Buccaneers American football team, previously failed to garner sufficient support to sell shares on exchanges in Hong Kong and Singapore.

However, United, which claims to have a global fan base of about 660 million and has won a record 19 league titles, is still one of the world's most valuable sports teams.

Although the listing has been planned for some time, the Glazer family originally claimed all the proceeds would go towards United's debt, angering fans.

A successful initial public offering would reportedly result in investors owning 42% of the shares available but only carrying voting rights of 1.3%.

Trading under the stock-market ticker Manu, shares rose but then pulled back to stand still at the $14 mark.

A statement from the Manchester United Supporters Trust (Must) read: "The Manchester United Supporters Trust has today called for a worldwide boycott of Manchester United sponsors' products, with support across the UK, Europe, Asia and the US.

"The boycott strategy is intended to send a loud and clear message to the Glazer family and club sponsors that, without the support and purchasing power of the fans, the global strength of the Manchester United brand doesn't actually exist."