Martin Sorrell's advertising and media giant WPP is looking to launch a joint venture (JV) in Vietnam, expanding in one of the fastest growing markets in the world.Burson-Marsteller, WPP's public relations and public affairs division, is to take a majority stake in the JV with local partner Chu Thi Company, the creator of Vietnam's first ever daily talk shows airing on official government national television channels."This investment continues WPP's strategy of developing its networks in fast growing markets and sectors," the statement said.Goldman Sachs has identified Vietnam as one of the next 11 economies to watch, with a population of 87m and a gross domestic product growth rate of 5.9%. WPP has been operational in the country for over a decade.The JV is still subject to regulatory approval, the group said.Shares in WPP have been performing strongly as of late, hitting a new 52-week high on Tuesday at 835p, some 8% higher than they were a year ago.BC