Tube manipulation specialist Tricorn said its main lender had put restrictions on its borrowing facilities while it continues talks with potential acquirers.
Tricorn, facing a cash crunch, had announced a formal sales process on 21 July.
'The company and its advisers have engaged in discussions with a number of parties, with such discussions ongoing,' it said.
Tricorn said that although it was currently operating within its borrowing facilities, 'there may be a requirement to operate beyond' them. 'Whilst the group's principal lending bank is expected to remain supportive, certain restrictions on these facilities are being imposed,' it added.
'It is expected that such restrictions would be eased in the event of a successful sale of one or more of the company's operations or an injection of funds, although there can be no certainty of a successful outcome in these matters.'