Stuart Mitchell, the Chief Executive at building materials group SIG, has purchased 53,000 shares just a few days after the company posted a decline in first half underlying pre-tax profit. Mitchell bought the shares at 180.00p a time, costing him a total of £95,400. Speaking last week, he said that the company continues to "expect to make further progress in 2013 consistent with our previous expectations, assuming normal weather conditions in the second half".However, he also warned that "while there are signs that market conditions are starting to improve in the UK, construction activity in Mainland Europe remains weak". The results showed that revenues in continuing operations fell slightly, by 0.7% to £692.2m, with like-for-like sales down 4.5%.Underlying pre-tax profit dropped to £30.2m from the prior year's £35.5m and revenue decreased to £1.27bn from £1.28bn.Mitchell's stake in the company now stands at 164,260 shares. Top Director BuysNew Europe Property Investments (NEPI) Director name: Mr Victor Semionov Amount purchased: 275,000 @ € 4.89 Value: €1,344,750New Europe Property Investments (NEPI) Director name: Mr Martin SlabbertAmount purchased: 200,000 @ € 4.89 Value: €978,000Intu Properties (INTU) Director name: Mr John Whittaker Amount purchased: 100,000 @ 311.76p Value: £311,760SIG (SHI) Director name: Mr Stuart Mitchell Amount purchased: 53,000 @ 180.00p Value: £95,400Newmark Security PLC (NWT) Director name: Mr Michel RapoportAmount purchased: 1,500,000 @ 1.40p Value: £21,000Top Director SellsMears Group (MER) Director name: Mr Robert (Bob) HoltAmount sold: 600,000 @ 417.33p Value: £2,503,980Lombard Risk Management (LRM) Director name: Mr Nicholas DaviesAmount sold: 2,600,000 @ 12.00p Value: £312,000Baronsmead VCT (BDV) Director name: Mr Peter LawrenceAmount sold: 21,523 @ 73.50p Value: £15,819NR