Jim Ratcliffe warned Manchester United he would have ended his bid to become a minority owner if it was not sealed before Christmas Day, according to financial documents released by the club on Wednesday.

British billionaire Ratcliffe agreed to buy a 25 per cent stake in the Premier League club for around £1.02 billion ($1.3 billion) on Christmas Eve.

But US Securities and Exchange Commission (SEC) filings released on Wednesday have revealed the INEOS chairman's patience had begun to wear thin shortly before an agreement was struck.

In the week before Christmas, Ratcliffe's company 'Trawlers Limited' "gave Manchester United a deadline of December 25, 2023 to accept its best and final proposal".

It led to an informal meeting of the board of directors on December 22 and a "robust discussion regarding the feedback from the offeror".

The board representatives noted Ratcliffe "could decide to withdraw (the) proposal if the board of directors was not prepared to move forward by December 25, 2023".

Ratcliffe's investment in United was subsequently agreed on December 24, bringing an end to a protracted saga that began when United's owners the Glazer family put the club up for sale in November 2022.

Ratcliffe struck a deal to buy 25 per cent of Class B shares held by the Glazers and up to 25 per cent of all Class A shares at a price of 33 US dollars (£26).

That offer for up to 13,237,834 Class A ordinary shares was confirmed on Wednesday.