After the debacle at Mackie last year, most observers felt that there were no more tales of woe to come from the clutch of Northern Ireland companies on the stock market. And until last Tuesday, the prospect of the bluechip of the Northern companies, Powerscreen, finding a £50 million black hole in its accounts was simply unthinkable.

For that very reason, the reaction in the market to the discovery of major irregularities at the Matbro subsidiary was one of shock. And the Powerscreen management, headed by Mr Shay McKeown, has a major repair job to carry out on its reputation if Powerscreen is ever again to enjoy the exalted rating it had among British engineering companies.

Assuming the Matbro situation can be sorted out quickly even at the expense of a £50 million write-off there is an argument to be made that Powerscreen shares are good value at their current level. At the 280p sterling price of last Wednesday, Powerscreen is trading on a 1999 p/e of around eight, based on revised forecasts for 1999 by London analysts. That is a cheap entry price for a share, which could become the focus of a takeover bid, with international groups like Ingersoll Rand, Caterpillar, JCB and John Deere all being mentioned as possible bidders.