Turkish Prime Minister Recep Tayyip Erdogan was to attend the opening Sunday of a Turkish group's headquarters in Germany _ alongside outgoing Chancellor Gerhard Schroeder, a staunch ally of his country's European Union membership bid. The two leaders were expected at the Cologne headquarters of the Union of European Turkish Democrats, a group that was founded last year and aims to strengthen Turks' integration in European society. Erdogan's trip follows a visit to Istanbul by Schroeder last month, and comes as Schroeder's Social Democrats negotiate with Chancellor-designate Angela Merkel's conservatives to form a new coalition government. Schroeder has consistently advocated bringing in Turkey as the EU's first Muslim-majority member, but Merkel has argued that the bloc would struggle to integrate the country. During her election campaign, she advocated offering Turkey a "privileged partnership" that would fall short of full membership. It remains unclear what stance the new government will take. The Social Democrats will take the Foreign Ministry _ which is to be led by Schroeder's chief of staff, Frank Walter Steinmeier. Turkey's EU membership talks formally opened Oct. 3. They are expected to last a decade or more, according to a report of The Associated Press.