EXCLUSIVE: Charlie Gibson's email to ABC Staff About Decision To Retire

ABC stunned the news world Wednesday with the revelation that Charlie Gibson is stepping down and being replaced by Diane Sawyer.

Now RadarOnline.com has obtained an email sent by Gibson about his decision.

In an email to his staff, Gibson wrote, in part: "...It has not been an easy decision to make. This has been my professional home for almost 35 years. And I love this news department, and all who work in it, to the depths of my soul...The program is now operating at a very accelerated, but steady, cruising speed, and I think it is an opportune time for a transition - both for the broadcast and for me..."

RadarOnline.com also obtained an email from network news prez David Westin. Addressing his news department, Westin wrote: "Diane Sawyer is the right person to succeed Charlie and build on what he has accomplished. She has an outstanding and varied career in television journalism...We are fortunate to have a journalist of Diane's proven ability and passion to step into the important position of anchor for World News..."