The US ABC network is planning a spin-off of its hit medical series GREY'S ANATOMY, featuring the character of DR ADDISON MONTGOMERY-SHEPHERD, played by Kate Walsh. The show's creator, Shonda Rhimes, is preparing a two-hour episode Grey's Anatomy, set to air in May (07), which would serve as the pilot episode for the proposed spin-off. If the network approves, the show will be considered for spot on the schedule next autumn (07). An ABC spokeswoman confirmed the plans, but said the plot line for the spin-off was being kept under wraps and no title has been selected. Grey's Anatomy has remained hugely popular in the US ratings since its premiere in April 2005.