The United States has formally asked Switzerland to extradite film director Roman Polanski, who fled sentencing in California on child sex charges in 1977, the Swiss justice ministry said on Friday. It said it would make a decision on extradition based on a hearing and on information provided by Polanski's lawyer, but that there was no deadline. “We will take the time that is needed,” spokesman Folco Galli said. Polanski will be able to appeal against any extradition decision to the Swiss Federal Criminal Court and, in the last instance, the Federal Supreme Court, the ministry said. US judicial sources have said the extradition process is complex and could take years if Polanski challenges it.