December saw some significant developments in the convenience channel in a number of markets, with Japan's Lawson Inc plotting a strategic alliance with Three F, Couche-Tard acquiring an Irish operator, its Canadian rival Sobeys launching a convenience concept and Morrisons returning to the sector in the UK. In other news, it emerged Kroger plans to trial a store format in the US while Lidl is continuing the march of the discounters across Europe. Here is just-food's round up of the big news stories from the world of grocery retail last month.