Shanghai Mayor Xu Kuangdi left on a four-nation tour yesterday that will focus on economic ties and urban development. The popular mayor is heading a city government delegation on a visit that includes stops in South Africa, Morocco, France and the Netherlands. He plans to return on September 11. The mayor is expected to meet Dutch Prime Minister Wim Kok and Transport Minister Tineke Netelenbos among other officials during his visit to the Netherlands. He also will tour Rotterdam's port facilities and get a glimpse of Dutch-style satellite cities and water projects. Shanghai is planning to build a deepwater port, the key project in the city's current five-year plan. It is also looking at ways to solve its housing and traffic problems as it expands into the suburbs. Foreign diplomats said that stops in Marseilles and Rotterdam will also focus on sister-city relations with those two cities. The mayor may also make a brief stop in Berlin to visit a Holocaust memorial. The Mayor's tour has sent foreign diplomats scrambling to reschedule meetings with senior city government officials to discuss preparations for the forthcoming Asian Pacific Economic Co-operation Forum. Preparatory meetings had to be cancelled due to the mayor's trip. Shanghai hosts the forum in October.