(Reuters) - London's stock markets sank deep into the red again on Tuesday as shares in pub operators and catering giant Compass Group dived on the back of the latest measures taken to contain the coronavirus, both domestically and globally.Shares of the world's biggest catering firm slumped 22.2% to their lowest since June 2013 after the company forecast half-yearly operating profit would come in way below expectations due to steps taken in Europe and North America to contain the spread of the..