NEW YORK, Sept. 7 (UPI) -- ABC News President David Westin revealed in an e-mail to the U.S. TV network's news division employees Monday he is stepping down at year's end.

Weston said he is leaving after 13 years at ABC News because the timing is right.

"Leading you has been a great privilege and a solemn responsibility -- a responsibility that I tried to fulfill for over 13 years by doing what I believed was best for this important news organization," Westin said in the e-mail reported on the ABC Web site. "I will root for your continued success long after I am gone.

"I've always admired those few who know when it's time to move on. This is the right time for me."

Westin noted ABC has gone through "a very difficult transformation made necessary by changes in our business and its economics," and now has new anchors for all of its programs.

"I am confident ABC News is better positioned for the future than it has been at any time since I came here in March of 1997," he said.

Westin said there are other things he wants to do professionally but didn't reveal what they are.

Anne Sweeney, co-chairman of Disney Media Networks and president of Disney ABC Television Group, learned of Westin's intention to leave a month ago.

She also sent a message to all ABC News employees, calling Westin "a tireless advocate for ABC News" who "helped reinvent our news organization, and positioned us for great success going forward."

"While it will be sad to see David leave, his desire to pursue other professional endeavors is understandable, and commendable, and I know you'll join me in wishing him nothing but the best," she said. "I'll be announcing a new leader for ABC News in the near future."