Grahame Gibson, chief operating officer of security group G4S, has sold 180,000 shares at 265.81p each for £478,458.Gibson has been involved in the security industry for 27 years, having joined the group's UK operating company in 1983 as the finance director.Since then, he has held a number of operational, management and board positions in the UK, US, Denmark, the Netherlands and Austria.Gibson joined the board in April 2005 and is the divisional president of secure solutions. He is currently a board member of the Ligue Internationale des Sociétés de Surveillance, an association of private security organisations throughout the world.Group turnover for the first half of 2010 was up 4% at constant exchange rates to £3.6bn from £3.5bn previously. Pre-tax profit was up 3% to £238.1m. Sales and underlying profits were slightly ahead of market expectations, despite the trading environment remaining challenging.Top Director BuysGeneral Electric Co (GEC) Director name: Mr Michael A. NealAmount purchased: 20,553 @ € 11.61 Value: € 238,651Bunzl (BNZL) Director name: Mr Michael J RoneyAmount purchased: 35,562 @ 764.79p Value: £271,975Hansteen Holdings (HSTN) Director name: Mr Richard Cotton Amount purchased: 100,000 @ 75.00p Value: £75,000Ukraine Opportunity Trust (UKRO) Director name: Mr Nigel Douglas PilkingtonAmount purchased: 10,000 @ $2.40 Value: $24,000Ukraine Opportunity Trust (UKRO) Director name: Mr Bertrand Ivan LipworthAmount purchased: 10,000 @ $2.40 Value: $24,000Ocado Group (OCDO) Director name: Mr David GrigsonAmount purchased: 15,000 @ 136.41p Value: £20,462Ocado Group (OCDO) Director name: Mr David YoungAmount purchased: 7,400 @ 135.84p Value: £10,052Top Director SellsG4S (GFS) Director name: Mr Grahame GibsonAmount sold: 180,000 @ 265.81p Value: £478,458Bunzl (BNZL) Director name: Mr Patrick LarmonAmount sold: 22,662 @ 764.79p Value: £173,317Bunzl (BNZL) Director name: Mr Brian MayAmount sold: 16,735 @ 764.79p Value: £127,988Bunzl (BNZL) Director name: Mr Paul Nicholas HusseyAmount sold: 7,844 @ 764.79p Value: £59,990