Flash Briefing: Stanford world's top MBA; Worst mining disaster since 1966; Naspers spends big in Russia; Brexit hits London houses hard

In global news headlines..... Turnover in the London housing market has fallen to its lowest level since the Global Financial Crisis ten years ago and those who do sell have accepted 11% less than their asking prices. The world’s largest iron ore producer, Brazilian group Vale, is in the global headlines today after the biggest mining disaster in more than 50 years.  California’s Stanford’s Graduate School of Business has topped the world’s best MBA list for the second successive year, shading its east coast rival Harvard. In South African related news, the Naspers share price opened fractionally lower this morning after Friday evening’s announcement it had paid more than a billion dollars to buy the 27% it did not already own in Russian company Avito.