Michael Sharp, the Chief Executive of retail giant Debenhams, purchased 100,000 shares on Tuesday, the same day the company reported a strong end to 2012, including record levels of sales in December, but warned heavy discounting had hit margins. Sharp, who was appointed to the role in September 2011, bought the shares at 109.5p a time, spending a total of £109,500. In the 18 weeks to 5th January, total sales values increased by 3.5%, while like-for-like sales grew by 2.9%. Over the five weeks to 5th January like-for-like sales increased by 5% compared to the year before and by 8.5% on 2010. However, the firm said margins took a battering as customers looked for bargains ahead of Christmas as well as in the traditional sale period. "We now expect gross margin for the year to be 10 basis points higher than last year rather than 20 basis points as previously guided," Debenhams commented. Top Director BuysDebenhams (DEB) Director name: Mr Michael SharpAmount purchased: 100,000 @ 109.50p Value: £109,500SerVision (SEV) Director name: Mr Gidon TahanAmount purchased: 1,075,269 @ 4.38p Value: £47,097Polar Capital Technology Trust (PCT) Director name: Mr Peter HamesAmount purchased: 6,000 @ 377.26p Value: £22,636Kentz Corporation Ltd. (KENZ) Director name: Mr David MacFarlaneAmount purchased: 5,585 @ 392.08p Value: £21,898Top Director SellsDelcam (DLC) Director name: Mr Edward B LambourneAmount sold: 60,000 @ 1,000.00p Value: £600,000Delcam (DLC) Director name: Mr Hugh HumphreysAmount sold: 60,000 @ 1,000.00p Value: £600,000