There had been rumours during the week that a company of the ilk of European contractors Technip or US-based Hatch was tied down in legal discussions regarding an acquisition.

Possible scenarios for the Clough family include a complete exit from the business or a merger with a larger organisation.

Legal circles in Perth were tight lipped on who may be involved, but Clough’s mix of civil, mineral processing and oil and gas experience may narrow possible partners down to someone like the Aker Kvaerner group, which boasts broadly similar business units.

Other possibilities include the UK's privately-owned Petrofac group, where former Clough CEO Rob Jewkes has taken an executive role.

However, a large article in the West Australian this morning triggered the trading halt. The company also delayed the release of its full year profits, originally due to be announced yesterday.

Clough icon, Harold Clough, last month said the family’s stake of 53% was for sale ‘at the right price’ given none of his children were interested in managing the engineering business. The news surprised both the company and investors at the time.

Since then Clough Ltd shares have risen from 42c in June to 56c yesterday.