Weekly round-up of the latest corporate announcements, including a takeover by Hammerson plc, a possible offer by GVC Holdings plc, an IPO by Mirriad Advertising plc, a reverse takeover and placing by Savannah Petroleum plc, a placing, open offer and Class 1 transaction by Xafinity plc, placings and related party transactions by Duke Royalty Limited, Seeing Machines Limited and Atalaya Mining plc, a placing by WANdisco plc, a joint venture between U and I Group plc and a consortium managed by McArthurGlen, a return of value to shareholders from Victrex plc and AGM notices from Victrex plc, Shaftesbury plc and easyJet plc.