LONDON, May 1 (Reuters) - The following FTSE 100 companies will go ex-dividend on Thursday, after which investors will no longer qualify for the latest dividend payout. According to Reuters calculations at current market prices, the effect of the resulting adjustment to prices by market-makers would take 4.73 points off the index. COMPANY (RIC) DIVIDEND STOCK OPTION IMPACT (pence) G4S 6.11 0.37 Kingfisher 7.49 0.63 London Stock Exchange 37.2 0.45 Mondi 142.9 (EUc) 1.79 Unilever 33.41 1.50 Among FTSE 250 companies going ex-dividend are: COMPANY (RIC) DIVIDEND (pence) Card Factory 6.4 Coats Group 1 (USc) Derwent London 28 Edinburgh 5.8 Investment Trust Elementis 4.35 Fenner 2.1 GCP 1.9 Infrastructure Investment Trust ContourGlobal 2.6 (USc) Hastings Group 8.5 J D Wetherspoon 4 Just Group 2.55 McCarthy & 1.9 Stone Morgan Advanced 7 Materials Playtech 23.9 (EUc) Rightmove 36 Senior 4.9 (Reporting by Helen Reid, Editing by Julien Ponthus)