No ex-divs on the FTSE 100 on July 20

LONDON, July 17 (Reuters) - No FTSE 100 companies will go ex-dividend on Thursday, although several mid-caps will go ex-div, after which investors will no longer qualify for the latest dividend payout. Among FTSE 250 companies going ex-dividend are: COMPANY (RIC) DIVIDEND (pence) Tritax Big Box Reit 1.28 Syncona 2.3 Vedanta Resources 35 (U.S. cents) (Reporting by Kit