Susan Lyne, a former top ABC Entertainment executive who most recently resigned as CEO of Martha Stewart Living Omnimedia, is the new CEO of the Gilt Groupe, a start-up e-commerce site.

She replaces Alexis Maybank, who helped launch the luxury Web site last November with former Doubleclick chief Kevin Ryan, one of the six e-companies owned by Alley Corp., which runs Web sites Alley Insider, Music Nation, Panther Express, ShopWiki and 10gen.

Maybank will remain chief strategy officer.

Lyne said that the offer to join Gilt Groupe came after Matrix Partners, the backer of Alley Corp., contacted her soon she announced in June her plan to leave Martha Stewart.

“They said what would rather do, work at a company where you are fixing other people’s mistakes or go somewhere and start something new?” Lyne said. “It’s an incredibly exciting opportunity.”