After a two-year tenure during which he earned the praise of transit advocates as a skilled and innovative leader, MTA Chair Jay Walder has announced that he will step down effective October 21. Walder, who was appointed by governor David Paterson in July 2009 and took the CEO position that October, will be taking the reins of the MTR Corporation, a Hong Kong-based rail company.

As MTA Chair, Walder brought a wealth of experience to the table, including six years at Transport for London and an earlier 12-year stint at the MTA in the 80s and 90s. His tenure as chair was marked by his response to the agency’s ever-tightening finances. At a time when huge debt loads and Albany transit raids placed big strains on the MTA’s budget, Walder was able to implement substantial efficiencies and bring innovative programs on line quickly, like the real-time bus information project known as BusTime. He also could not avoid enacting the biggest round of service cuts the NYC transit system has seen in a generation.

Walder will be departing at an eventful time for the agency. Its contract with the TWU Local 100 expires at the end of the year, and negotiations are expected to ramp up in the following months. The MTA recently announced $2 billion in cuts to its five-year capital program, which still leaves a $9 billion hole. Some combination of fare hikes, service cuts, and deteriorating conditions looms unless new revenue sources are secured or the MTA abandons mega-projects like the Second Avenue Subway.

There are not many people out there who can bring the same degree of experience and competence that Walder brought to the job. We’ll have more on Walder’s departure as the story develops.

Update: We’re hearing that staff at MTA HQ were taken by surprise by Walder’s departure, though Liz Benjamin tweets that Senator Marty Golden doesn’t believe he was pushed out by Governor Cuomo.