Manchester United have slashed the price of their shares ahead of their debut on the New York Stock Exchange on Friday.

The club had been set to sell their shares for between $16-$20 (£10.20-£12.80) a share but cut them to $14 late on Thursday following negative comments from Wall Street analysts and Facebook's disappointing stock market debut in May.

Even after the cut United will be valued at $2.3bn (£1.5bn) making them the most valuable football club in the world. Real Madrid, their closest rivals in financial terms, are valued at $1.88bn, according to an annual ranking by Forbes magazine.

The shares are being sold by the Glazer family, a US-family who made their fortune with shopping malls and trailer parks and also own the Tampa Bay Buccaneers.

The Glazers bought United in 2005 for about £800m. They are selling 16.7m shares, equal to a 10% stake, and will raise about $330m. The family will net about about £90m from the flotation.

The club claim a global fan base of about 660m and have won a record 19 league titles. Their share sale will be the largest sports listing on record, surpassing World Wrestling Federation's $190m IPO in 1999, according to Thomson Reuters.

It will also be the most high-profile since Facebook's ill-fated debut on the Nasdaq stock exchange in May. The social network's much hyped share sale proved a bust and shares initially sold at $38 are now worth $20.

Wall Street analysts have warned they believe United's sale too could be a disappointment. "I'm calling this son of Facebook," said David Menlow, president of the research firm IPOfinancial.com.

He said too little of the money being raised looked like it was going to be invested in the club, the club had too many debts and it was not clear how they intended to grow as a business.

"Sports franchises have this emotional flourish, then everybody wakes up and wonders, 'Do I really want to own this?'" he said.

Sam Hamadeh, founder New York-based analyst PrivCo, called United "a collectible not an investment". "This is one for the rabid fan," he said.

This is the Glazer family's third attempt at a share sale having previously scrapped efforts to sell shares on exchanges in Hong Kong and Singapore.

Those sales failed as investors balked at United's proposed dual class share structure. Under the US listing the family will retain control of the club through class B shares that have 10 times more voting power than the publicly traded class A shares.

The company is also taking advantage of recently introduced US laws that limit the financial disclosures it must make. United is raising capital as an "emerging growth" company under president Barack Obama's recently passed Jumpstart Our Business Startups, or Jobs Act.

The move means United will not be required to file quarterly reports or be subject to the same level of financial scrutiny as other US-listed firms for five years.

Some of the proceeds from the sale are expected to be used to pay down some of the 134-year-old club's debt, which was last reported to be around £423m. But the Glazer family had originally claimed all the proceeds would go towards United's debt, angering some fans.

A leading fans group has called for a boycott of the club's sponsors in protest at the terms of the share sale.

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."