The 'Les Miserables' actress - who married Adam Shulman in Big Sur, California in late September - is set to toast the start of 2013 by singing alongside the 54-year-old 'Celebration' singer at a star-studded bash organised by her wedding dress designer Valentino in Switzerland.
A source told the New York Post's Page Six, that the 29-year-old actress is staying at the designer and his partner Giancarlo Giammetti's luxurious chalet in the exclusive mountain resort of Gstaad.
Valentino is throwing a New Year's Eve (NYE) party on December 31, 2012 at the members-only Eagle Ski Club.
The insider said: "Rumours are flying that both Madonna and Anne Hathaway will take turns serenading the legendary designer, and they might even do a duet at midnight. Valentino's NYE bash is the hottest ticket in Europe, and people are flying in from all over the world for it. Valentino is reportedly spending 500,000 euros on caviar, champagne, music, food, décor and fireworks at Wasserngrat Mountain."
Madonna is said to be attending the bash with her daughter Lourdes, 16, who have been spotted skiing in the area in recent days, while Anne will have her husband there to kiss him at midnight.