Private hospital firm Spire Healthcare has given Toscafund more time to formalise its £1billion takeover bid.

The FTSE 250 said it had extended the deadline for Toscafund – run by hedge fund tycoon Martin Hughes – to finalise a 250p-a-share bid from 5pm yesterday to August 21.

It is the fourth time it has extended the deadline since the firm made its first approach in May.

Toscafund, set up in 2000 by Hughes – known as ‘the Rottweiler’ for his aggressive dealmaking – is Spire’s second-largest shareholder.

Spire runs 38 hospitals and more than 60 clinics in England and Wales. It treated 1.4million people last year and is the leading private provider of knee and hip operations by volume.

It runs workplace health services for about 1,400 employers.

Toscafund tabled its first bid on May 14 at a 66 per cent premium to Spire Healthcare’s closing price the previous day, valuing the company at around £1billion.

In an update to investors, Spire said Toscafund had ‘substantially completed its due diligence’ and that it had requested extra time to finalise its financing arrangements.

The British investment firm built a nearly 11 per cent stake in Spire while opposing a 250p-a-share offer by Ramsay Healthcare of Australia in 2021. It has since grown its holding to around 18 per cent.

In May, Spire said that while talks were at an early stage, the board ‘would be minded to recommend unanimously… the possible offer’ to shareholders.

It came after the private hospital group told investors in January that it was in talks with Bridgepoint and Triton, also private equity firms, though no deal was forthcoming.

Shares in Spire rose 0.21 per cent to 235.5p this morning, after gaining 39.4 per cent this year.