Adam Walker, the outgoing Finance Director at data publishing and events firm Informa, has reduced his stake in the FTSE 250 group by 344,483 shares. Walker, who two weeks ago announced his intention to become Finance Director at GKN, disposed of the shares at 554.26p, earning himself £1.91m. At the start of this week the company said it is on track to hit expectations this year after a 'solid' third quarter with good performances from across each division.However, it also warned that the recent strength of the sterling against the US dollar, euro and Brazilian real, has been "unhelpful" to its results. Nearly half of group sales are in US dollars or currencies closely aligned with the greenback.The company saw positive organic growth across the board during the first nine months of the year in spite of the absence of the Formobile exhibition in Brazil, which only takes place every two years. Group adjusted organic revenues increased by 1.1% during the first three quarters.Like-for-like (LFL) revenue growth in Academic Information was 4%, a slight pick-up from the half-year stage.Walker, who will exit the company at the end of 2013, now owns 22,663 shares in the group. Top Director BuysStobart Group Ltd. (STOB) Director name: Mr Iain FergusonAmount purchased: 100,000 @ 130.00p Value: £130,000Asian Plantation Ltd. (DI) (PALM) Director name: Mr Datuk Amar Leonard Linggi JugahAmount purchased: 25,000 @ 201.00p Value: £50,250Asian Plantation Ltd. (DI) (PALM) Director name: Mr Dennis MelkaAmount purchased: 25,000 @ 200.00p Value: £50,000IMI (IMI) Director name: Mr Carl Peter ForsterAmount purchased: 3,000 @ 1,567.00p Value: £47,010Centrica (CNA) Director name: Mr Rick HaythornthwaiteAmount purchased: 12,500 @ 356.58p Value: £44,572Geopark Limited (GPK) Director name: Mr James F ParkAmount purchased: 3,500 @ 515.00p Value: £18,025Magnolia Petroleum (MAGP) Director name: Mr Ronald Sanford HarwoodAmount purchased: 500,000 @ 2.80p Value: £14,000Home Retail Group (HOME) Director name: Mr John CoombeAmount purchased: 6,952 @ 195.80p Value: £13,612Home Retail Group (HOME) Director name: Mr Jacqueline de Rojas Amount purchased: 5,324 @ 195.80p Value: £10,424Home Retail Group (HOME) Director name: Mr Cath KeersAmount purchased: 5,324 @ 195.80p Value: £10,424Top Director SellsIMI (IMI) Director name: Mr Martin J LambAmount sold: 300,000 @ 1,503.00p Value: £4,509,000Informa (INF) Director name: Mr Adam WalkerAmount sold: 344,483 @ 554.26p Value: £1,909,331Menzies(John) (MNZS) Director name: Mr D J JenkinsonAmount sold: 153,750 @ 812.00p Value: £1,248,450Menzies(John) (MNZS) Director name: Mr D J JenkinsonAmount sold: 37,500 @ 820.00p Value: £307,500Dairy Farm International Holdings Ltd. (Singapore) (DFI) Director name: Mr Michael KokAmount sold: 15,300 @ $11.51 Value: $176,040Dillistone Group (DSG) Director name: Mr Giles Robin Fearnley Amount sold: 140,000 @ 111.00p Value: £155,400Proton Power Systems (PPS) Director name: Dr Faiz Francois NahabAmount sold: 2,300,000 @ 6.15p Value: £141,450Law Debenture Corp. (LWDB) Director name: Ms Caroline BanszkyAmount sold: 10,000 @ 525.00p Value: £52,500NR