Institutions which purchased Kingspan shares from its former director, Mr Brendan Murtagh, on Friday, saw the price of their shares rise by 17 cents (13p) to close at €2.45 (£1.93) yesterday. This means collectively the institutions made a paper profit of €2.2 million (£1.73 million) on the day.

A company statement yesterday said Mr Murtagh sold the 12.8 million shares at €2.28 (£1.80). For this he received £23 million - but would have received £1.6 million more if he had sold at yesterday's price. He now retains a 3.6 per cent stake in the company.

It is understood the shares, placed by ABN-AMRO Stockbrokers, were taken up by most of the major Irish institutions.