DUBAI, Sept 29 (Reuters) - London-based fund manager Ashmore Group Plc has hired prominent investment strategist John Sfakianakis to establish its first Middle East ****** in Riyadh, months before Saudi Arabia opens its stock market to direct foreign investment. Sfakianakis was appointed to the new post of regional director for the six Gulf Cooperation Council (GCC) countries, a source familiar with the matter said on Monday. He is expected to manage Ashmore's plans to invest international and Gulf money in regional markets. ...