BRUSSELS - The European Union Wednesday threatened a lawsuit against France over the expulsion of gypsies, saying French President Nicolas Sarkozy's government probably breached EU rules on the free movement of citizens. The European Commission started infringement proceedings over France's expulsion this year of more than 1,000 Roma, as gypsies from Eastern Europe are known, back to Romania and Bulgaria, both of which joined the EU in 2007. The French move included the dismantling of gypsy camps. 'We have opened a procedure of infraction against France,' Justice Commissioner Viviane Reding told French radio Wednesday. 'It's a question of if there has been discrimination.' The commission, the 27-nation EU's regulatory arm, decided to send the French government a letter of formal notice, the first step in a process that could lead to a complaint at the European court. France will conduct 'a detailed analysis of the commission's letter,' a spokeswoman for the French Foreign Ministry said by telephone. 'There have been a certain number of misunderstandings between France and the commission,' said the spokeswoman, who cannot be named according to ministry ground rules. French President Nicolas Sarkozy's office 'won't publish any reaction,' spokesman Franck Louvrier said by telephone. Calls to the Justice and Immigration ministries weren't returned immediately. France's treatment of Roma, members of an ethnic minority who are EU citizens, rose to the top of the European political agenda in mid-September when Reding linked the policy to events during the Second World War and EU government heads debated the matter two days later at a Sept. 16 summit. The European Parliament, the Catholic Church and newspapers including Le Monde, the Financial Times and The New York Times have denounced France's policy. EU law prohibits governments from targeting ethnic minorities. European legislation does allow governments to expel citizens from other EU countries after three months for reasons of public order or should the people in question have insufficient economic resources or pose a burden to the domestic health- care system. ^-0-< With assistance from Gregory Viscusi and Helene Fouquet in Paris. 