Proceeds from hundreds of items and experiences, ranging from an afternoon of shopping with former Barney's creative director, Simon Doonan, to backstage passes at concerts by Lady Antebellum or James Taylor, will benefit four environmental charities.

The annual auction, now in its third year, has raised about $5 million for its beneficiaries, which this year includes Oceana, the Natural Resources Defense Council, the Central Park Conservancy and Conservation International, said Christie's head of communications Toby Usnik.

Proceeds will be directed toward each organization's water-conservation projects.

Items up for bid at the online auction, which goes live on Thursday and runs through April 19, include a 1989 Fender American Vintage guitar signed by Pearl Jam, a two-week Kenyan safari and a private lesson in high fashion posing, photo movement and runway walking from Canadian model Coco Rocha.

Other offerings include actress Cameron Diaz recording your outgoing voicemail message, a private Empire State Building tour for 12, a day spent with editors at O Magazine and a paid internship at fashion house DKNY.

A live auction at Christie's on April 11 will feature an international Alain Ducasse-inspired culinary tour, diving in the Cook Islands with oceanographer Sylvia Earle, a Tribeca Film Festival package, and a week of sailing and diving aboard the Hemisphere, the world's largest luxury sailing catamaran.

Works by artists including Simon Cardwell, Christopher Pulitzer Leidy, Gail Tobias and others will also be auctioned online, along with less expensive items.

Susan Rockefeller, philanthropist and environmentalist who along with husband David Rockefeller has co-chaired the Green Auction since its inception, has designed two necklaces, each accented with a Swarovski crystal and selling for $100.

They are available with other items in the online sale at BidtosavetheEarth.charitybuzz.com starting on Thursday.

Coppy Holzman, CEO of the online auction site Charitybuzz.com, said that putting the lion's share of items online adds a level of international accessibility.

"Anyone, anywhere can contribute to the cause," said Holzman.

(Reporting by Chris Michaud; editing by Patricia Reaney)

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