Manchester United's valuation on the New York Stock Exchange (NYSE) plunged by more than 500 million ($628 million) on Tuesday -- its biggest daily percentage drop in value since being listed in 2012 -- amid reports that the Glazer family have shelved plans to sell the club.

After closing at $23.64 a share on Friday, the United stock price fell to $19.35 at close of business on Tuesday -- an 18.15 percent drop in value. The valuation had fallen as low as $18.50 a share at one stage during trading, wiping more than 20 percent off the club's value, before recovering ahead of the 4 p.m. ET closing bell.

Prior to Tuesday's huge drop in value, the previous record fall in one day was a 13.8 percent drop in March 2020.

Reports in England on Sunday said that United owners the Glazer family were considering taking the club off the market after initiating a sale process, including a search for outside investment last November.

INEOS founder Jim Ratcliffe, Britain's richest man and a boyhood United supporter, and Qatari billionaire Sheikh Jassim bin Hamad Al Thani have both been engaged in a lengthy process to buy the club from the Glazers, but sources have told ESPN that neither has met the American family's 6 billion ($7.53 bn) valuation of the club.

United's market value on the NYSE prior to Tuesday's valuation drop was listed as 3.15 billion ($3.5 bn) and finished Tuesday at approximately 2.55 billion ($3.2bn), substantially lower than the Glazers' valuation.

And while the team's form on the pitch has seen them lose two of their first four Premier League games this season, the trigger for Tuesday's price plunge is likely to be investors selling off shares amid concerns that the club will not be sold to Ratcliffe or Sheikh Jassim.