Retailer Wm Morrison said on Thursday it is "making good progress" with the search for a new chief executive as Dalton Philips is due to step down next Monday.Philips was fired last month after delivering the worst Christmas performance of the Big Four supermarket groups. Like-for-like sales excluding fuel fell 3.1% in the six weeks to 4 January.Meanwhile, finance director Trevor Strain will chair the management board.Chairman Andrew Higginson said: "With Trevor Strain chairing the management board, together with the retailing strength and depth that I've seen in my short time at Morrisons, I'm confident that it will be business as usual during this transitional period."Also on Thursday, the group scrapped its controversial fruit and veg mist machine, an idea introduced by Dalton Philips five year ago.The misting machines received criticism from analysts and members of the board, accusing Philips of trying to move upmarket.Roger Owen, a board director, said: "You don't need misting - the stores are not air-conditioned. It is a waste of money, a waste of time and it does carry a risk unless you spend a significant amount on maintenance."A spokesman for Morrisons said the group was "going back to basics, using simpler refrigeration techniques".Shares in Wm Morrison rose 2.5% to 184.3p on Thursday at 12:14.