Solid Christmas for UK supermarkets before uncertain 2017

By James Davey LONDON (Reuters) - Britain's three quoted major supermarkets are expected to report this week that they enjoyed solid Christmas trading, though investor concern about a potential squeeze on consumer spending in 2017 means the focus is on their outlooks. Shares in market leader Tesco and Morrisons, the UK's fourth biggest grocer, soared 38 percent and 55 percent respectively in 2016, reflecting a recovery in trading.