Mid-cap share tip of the week: Booker Stuart Rose is famous for transforming the fortunes of Arcadia and Marks & Spencer. His right-hand man at those retailers, Charles Wilson, has a lower profile but has arguably achieved an even greater turnaround at Booker, Britain's largest cash and carry wholesaler. When he took over the company in 2005 it was suffering from heavy debts and sharply falling sales. But Mr Wilson has taken a firm hold of the business, stripping out costs and steadily increasing the profit margins on its £4bn turnover. Richard Hallett, who owns Booker shares in his Marlborough UK Leading Companies fund, said there was "an attractive turnaround story" at the company. While he admires Mr Wilson, his presence is not the only reason for holding the shares. "In May last year Booker acquired another wholesaler, Makro UK, for around £150m," Mr Hallett said. That acquisition has now been cleared by the Competition Commission, which opens the way for Mr Wilson to begin to improve margins at Makro. There are significant synergies in areas such as purchasing power and distribution hubs, which will increase the competitiveness of the combined group. Booker is also building up the online side of its business and has launched a fledgling operation in India, which "could be very promising," Mr Hallett said.