Australian investment firm Macquarie is set to walk away from talks to buy a stake in TalkTalk's wholesale division, PlatformX Communications (PXC).

As reported by The Telegraph, talks between the two have stalled over a £450 million ($570m) deal.

The report doesn't specify a reason for Macquarie's decision to halt negotiations.

Macquarie had been interested in snapping up the 40 percent stake in the business, giving PXC a value of £1.2 billion ($1.5bn).

Sources told the publication that the deal is off for now.

“It’s fine for the lenders to reject it but at some point they need to come up with their own counter-proposal. So far, there’s no sign of that happening, though," said a TalkTalk shareholder source.

TalkTalk, Britain's fourth-biggest broadband operator with 3.8 million customers, currently has a debt pile of £1bn ($1.27bn) and has been looking to sell off some of its assets to clear the debt.

In September, TalkTalk outlined plans to split into three standalone companies, its B2B Wholesale Platform, TalkTalk Consumer, and TalkTalk Business Direct.

Macquarie's interest in the company's wholesale division dates back to earlier this year, when it was reported that it had opened talks to buy the unit.

At the same time, UK mobile carrier Virgin Media O2 was heavily linked with a takeover of TalkTalk's consumer unit.

Founded in 2003 as a subsidiary of mobile phone retailer Carphone Warehouse, TalkTalk founder Charles Dunstone spun off the firm to become an independent company in 2010.

The company serves more than four million customers in the UK and is understood to have been up for sale in the last couple of years.

TalkTalk sold off its SME and enterprise-focused connectivity unit to its own shareholders for £95 million ($120m) in late 2023.