Supermarket shares were set to rise on the London Stock Exchange today as a full-scale bidding war for Morrisons erupted over the weekend. Tesco, Sainsbury's and Marks & Spencer were poised to move higher after a fresh bid for Morrisons led by US private equity firm Fortress sparked a takeover battle that could rumble on all summer. Fortress has teamed up with a division of Koch Industries, run by the billionaire Koch family which is one of the biggest donors to the US Republican party, and Canadian pension giant CPPIB to table a bid at 254p per share, valuing Morrisons at £6.3billion.