Swiss authorities arrested the film director Roman Polanski late Saturdayas he arrived at the Zurich airport, paving the way for his possible extradition to the United States in connection with a 32-year-old sex case. Polanski, 76, a French citizen, was detained as he arrived to receive an award at the Zurich Film Festival. Although he is expected to oppose extradition, the arrest raised a strong possibility that Polanski would be returned to the United States to face sentencing under his conviction for having had sex with a 13-year-old girl in 1977, when Polanski was 44. Polanski was initially indicted in 1977 on six felony charges that included rape, sodomy and providing a controlled substance to the girl. He eventually pleaded guilty to one count of having sex with a minor but fled the country after becoming convinced that the judge in the case, Laurence J. Rittenband, meant to backtrack on a plea arrangement and send him back to prison. The Swiss Justice Ministry said in a statement that Polanski, the director of celebrated films like 'Chinatown' and 'Rosemary's Baby,' was put in 'provisional detention' pending extradition based on the arrest warrant from the United States. In Los Angeles a representative for prosecutors described the arrest as all but inevitable in a game of cat and mouse they had never stopped playing. Polanski, though a French citizen, has long owned a home in Switzerland near the luxury resort of Gstaad. Why Polanski would suddenly be arrested after flying in and out of Zurich without trouble for years flummoxed his Hollywood friends on Sunday. Sandi Gibbons, a spokeswoman for the Los Angeles County district attorney's office, said it was simply a matter of having enough advance notice that Polanski would visit a country in which he was vulnerable. The victim in the case, Samantha Geimer, has long since publicly identified herself and expressed forgiveness for Polanski. Assuming Polanski does not waive his right to appeal the extradition, he can challenge the arrest warrant and any eventual extradition order, said Guido Balmer, a spokesman for the Swiss Federal Justice Department, and appeal both issues in the Swiss federal penal court of justice. If he were to lose those appeals, he could then get a final hearing on both issues at the Federal Court of Justice. 