Justice Ministry spokesman Folco Galli says "It won't be long" before a decision on the extradition request. He declined to be more specific.
The 76-year-old director fled the U.S. on Feb. 1, 1978, the day he was to be formally sentenced for having sex with a 13-year-old girl.
He was arrested on Sept. 26 as he came to receive a lifetime achievement award at a Zurich film festival. He has been under house arrest at his chalet in the resort of Gstaad since December, when he was released on $4.5 million (euro3.59 million) bail.
Polanski would be allowed to appeal extradition.