Portman, Kidman sign props for charity

London: Hollywood beauties Natalie Portman and Nicole Kidman are helping raise money for charity by signing their movie props for the Screen Actors Guild`s annual auction.

While Portman, who won the Best Actress trophy at the SAG awards on Sunday, has signed a `Black Swan` jewellery box, Australian star Kidman autographed a comic book from her drama `Rabbit Hole`.

Other items going under the hammer included a pair of boxing gloves signed by `The Fighter` co-stars Mark Wahlberg and Christian Bale, a website reported.

The sale will benefit the SAG Foundation for literacy, Book PALS and Storyline Online.

The auction, which began on January 27, closes today, a day after the 2011 SAG Awards took place in Hollywood.