Mayor Bloomberg has appointed a new technology czar as his administration grapples with overbudget and delayed projects.

Rahul Merchant, who worked in technology leadership roles for Merrill Lynch and Fannie Mae, was appointed the city’s chief information and innovation officer as well as commissioner of the Department of Information, Technology and Telecommunications.

Announcement of Merchant’s appointment came with a subtle acknowledgment of the problems many city technology projects are experiencing.

“Merchant will report directly to Mayor Bloomberg and will oversee the city’s information- technology development and management across all city agencies, with a focus on delivering technology projects on time and on budget,” a press release said.

Merchant succeeds Carole Post, who reportedly clashed with Deputy Mayor Caswell Holloway over botched tech projects, such as NYCWin — the municipal wireless network that cost $500 million to build and $40 million annually to operate. The system is sorely underused.