Architectural ranges sold under the Welsh//Slate brand by Alfred McAlpine Slate have been discontinued, although roofing slate continues to be available as accounting irregularities at the Alfred McAlpine Plc subsidiary are investigated.

The Welsh//Slate architectural products were displayed in a showroom at the Building Design Centre in Islington, London, and at a new showroom opened last year in Belgium.

Alfred McAlpine Plc announced in February that they had uncovered "material accounting irregularities" at their Welsh Slate subsidiary in Wales, where a new £6million roofing tile factory was opened last year (see NSS April and July issues).

The factory, with six Pedrini bridge saws, two 27-bladed Pedrini Arco secondary saws and three tile lines, replaced the ages old tradition of hand splitting the slates with modern sawing technology.

Chris Law, the managing director of the subsidiary that he told NSS last year had seen sales treble to £25million in the decade to 2005, was not contactable at the Welsh//Slate head offices at Penrhyn Quarry when NSS called. Operations director Geraint Roberts was also uncontactable there. Alan Smith is currently heading the business, reporting directly to Alfred McAlpine Plc\'s group chief executive, Ian Grice.

Alfred McAlpine Plc say an investigation by an internal audit team has uncovered what is described as a misrepresentation of production volumes and sales at the slate subsidiary.

In addition, say Alfred McAlpine, slate had been pre-sold at "substantially discounted prices".

Although investigations continue, the Board have told investors that they believe there will have to be a restatement of the 2005 net assets of the business by approximately £11million. The Alfred McAlpine group\'s 2005 figures show £42.1million pre-tax profit on sales of £1,057million. A reduction in pre-tax profit of the slate business in 2006 of about £13million is expected by Alfred McAlpine Plc.

And the Board believes that there will continue to be a material impact on the profitability and cash generation of the slate business this year, which it expects to make increased losses.

Just before the announcement, Alfred McAlpine shares had reached a high of more than 600p. After the announcement they fell to a low of 430p.

The preliminary financial report due on 15 March was delayed. The company expect to publish the report before the end of April.