Golden Gate University is starting a new program with a semester at GGU in San Francisco and a semester at University of Paris X at Nanterre. You end up with a US LLM and a French Diploma d'Universite (DU).

http://www.ggu.edu/school_of_law/academic_law_programs/llm_jd_programs/llm_sjd_international_legal_studies/the_paris_san_francisco_llm_du_program

Unfortunately this program was put on "hiatus" and it's unclear whether it will be resumed. Too bad because I participated in it and it was great.