Shares in Centaur Media, publisher of the The Lawyer and Marketing Week, lost almost a third of their value on Friday after the company issued a profit warning and said recruitment advertising revenues had tumbled 66 per cent over the past year.

The news triggered a 30 per cent drop in the share price to 23¾p and prompted a chill across the business-to-business publishing sector as investors feared the recession was having a deeper impact than expected.