SHANGHAI, 5 Nov, 2014 (AFP) - O'Grady, in Shanghai ahead of the WGC-HSBC Champions event which begins Thursday, said he had asked the European Tour's board of directors to start the process of appointing his successor.
The European Tour said in a statement it would make no further comment on the appointment process until the season-ending DP Tour Championship in Dubai in two weeks' time.
Ryder Cup star Justin Rose, the 2013 US Open champion, was one of the first players to pay tribute to O'Grady after the announcement.
"It's a shame that he's stepping down," Rose told AFP at Sheshan International Golf Club.
"He's had a good reign, a long reign and overcome challenges with the economic downturn during that time, especially in mainland Europe.
"In recent times, one of the things I've been talking to George about is really just trying to get some of the historic events back on The European Tour, British Masters for example.
"As he rolls out of his position, hopefully tournaments like that will come back on to the calendar and he can take some credit."
O'Grady will remain in his position until his successor takes office.
He was only the third chief executive in the Tour's history when he took over at the beginning of 2005 from Ken Schofield, who had been in charge for 30 years.
O'Grady's most notable achievements were the creation of the Race to Dubai and in 2013 the "Final Series" of four big-money European Tour events. This year's series began last week with the BMW Masters, also in Shanghai.
He also took part in the process that saw golf reinstated at the Olympic Games from Rio 2016.
"In the aftermath of what I believe to have been the best presented Ryder Cup since my first involvement in the contest at Royal Lytham in 1977, I felt this was the right time to ask the board to begin the search for my successor," O'Grady said in a statement issued in Shanghai.
"I have agreed with the board to stay not only for the time it takes to appoint a new CEO but also for sufficient additional time after that to see them properly settled in.
"The board also agreed that, at that stage, I will take up a role as president of international relations which will see me represent the European Tour through the Olympic Games in 2016."