NEW YORK CITY-Metropolitan Transportation Authority chairman and CEO Jay H. Walder formerly resigned from the MTA’s top post on Thursday afternoon. Walder, who began his career at the MTA in 1983, will be joining the MTR Corp. in Hong Kong as CEO and a member of the board of directors there. His resignation is effective on October 21, 2011.

In a MTA statement announcing his resignation, Walder says the city is “fortunate to have thousands of dedicated men and women who work so hard to provide these critically important transportation services to millions of people” everyday. “I believe that we have accomplished quite a lot in a short period, with the support of two Governors, the Mayor, a hard-working board and many others,” he says.

During his time at the authority, Walder headed the MTA’s capital program budget office, later serving as chief of staff and then chief financial officer, playing a major role in the advent of the MetroCard and subway countdown clocks. He became CEO and chairman in 2009.