Hire specialist Hewden is nearing collapse after failing to find a new financial backer.
The company has been racing against the clock to refinance £190m of borrowings, which are due to expire in the coming months.
It has been working with restructuring specialist Deloitte, which is looking to refinance or sell the business.
But Sky News has reported that the group’s owner, Sun Capital Partners, has called in EY to act as administrator, with sources saying talks with potential backers, including Alchemy Partners, have failed to materialise.
An announcement on EY’s appointment is expected to be made this week.
In a statement made in October, the company said it had been affected by market uncertainty following the vote to leave the EU, although it remained hopeful of finding a backer.
“The vote has adversely affected a number of large construction and capital investment projects,” it said at the time.
“The company is in constructive dialogue with stakeholders to resolve the situation in a consensual manner and is optimistic that a positive solution will be found.
“The company is working with its advisers Deloitte to reach agreement with lenders on an extension of its debt facilities, while also testing market appetite for a sale of the business.”
In its most recent accounts the company posted a pre-tax loss of £16.6m on sales of £105.9m.
Former Speedy Hire chief operating officer Adrian Murphy was named chief executive of Hewden in February 2015.
He took over from Kevin Parkes, who left after five years with the business.