French Finance Minister Christine Lagarde emerged as the leading contender to replace Dominique Strauss-Kahn at the International Monetary Fund as developing nations failed to unite behind a candidate. US Treasury Secretary Timothy F. Geithner called for the quick appointment of a new managing director yesterday while the Obama administration avoided backing any one person. “We want to see an open process that leads to a prompt succession,” Geithner said in a statement. John Lipsky, the Washingtonbased IMF’s acting managing director, “will provide able and experienced leadership to the Fund at this critical time for the global economy,” Geithner said. European officials moved to maintain control over the institution that approved a record $91.7 billion in emergency loans last year and provides a third of the euro-area’s bailout packages. Italy and Sweden backed Lagarde, while German Foreign Minister Guido Westerwelle said he holds her in high esteem, the first public hint of German support.