NEW YORK -- The head of an agency coordinating more than 60 construction projects in and around ground zero resigned Tuesday after two years on the job.

Charles Maikish, executive director of the Lower Manhattan Construction Command Center, said he had only agreed to take the job for two years and planned to return to the private sector.

"It's time for me to move on," Maikish said Tuesday.

He said downtown is busier than ever, and work is progressing on the dismantling of a 40-story skyscraper that sat vacant for years after it was damaged by the collapse of the World Trade Center on Sept. 11.

"Lower Manhattan is a forest of crane booms," he said.

The construction command center was created by the governor and mayor to help manage ongoing projects at the 16-acre trade center site and dozens of other simultaneous construction projects downtown, including creation of a city transit hub, a new Goldman Sachs headquarters and massive street repairs.

The command center is solely responsible for taking down the former Deutsche Bank building, which officials say will be complete by the end of the year. The project has been complicated by the removal of trade center dust and other toxins, and the discovery of hundreds of human bones.

Maikish, who said he will stay on until July, was most recently a real estate executive at JP Morgan Chase and at Columbia University. One of the workers who helped build the twin towers in the late 1960s, he later worked for more than two decades at the Port Authority of New York and New Jersey. He was responsible for the trade center in the 1990s, helping it rebuild after the 1993 truck bombing and with redevelopment that included its busy shopping mall.

"It is through the hard work and dedication of people like Charlie that Lower Manhattan has been able to experience the remarkable turnaround it has since 9/11," said Dan Doctoroff, deputy mayor for economic development and rebuilding.