Shares in Wolseley slumped 10.7 per cent to 3,730p per share after the plumbing and heating group slashed its outlook for revenue growth this morning.
Wolseley said it expected to generate like-for-like revenue growth of about four per cent in the six months to January 2016, down from a six-month forecast of six per cent it gave in June.
"Industrial markets in North America, which account for about 15 per cent of revenue in the region, were challenging in the fourth quarter and we expect this to continue," said chief executive Ian Meakins.
"We expect a continued steady recovery in Nordic markets, although the heating market in the UK is expected to remain very competitive with little growth."
This sent Wolseley to the bottom of the FTSE, despite the group posting an 11 per cent rise in profits to £857m.