TRENTON After six years as state comptroller, Matthew Boxer will be stepping down to take a job in the private sector, Gov. Christie announced Thursday.

Boxer "shined significant light" on problems at the state and local level, "because of the resources we gave him," Christie said at a Statehouse news conference.

He said Boxer's choice to step down was "regrettable for people of the state and me."

Boxer announced in July that an investigation by his office had turned up "widespread fraud" in 15 school districts, with public employees lying about their incomes to receive free lunches for their children.

Last year, he issued a report critical of cronyism and mismanagement at the Delaware River Port Authority, which is now under investigation by the U.S. Attorney's Office.

To replace Boxer, Christie nominated Marc Larkins, who has been chief executive officer of the New Jersey Schools Development Authority since 2010. The Schools Development Authority oversees school construction statewide.

Christie said Larkins had cleaned up "rampant patronage" at the authority.

The governor nominated Charles McKenna, his chief counsel, to succeed Larkins.

He announced that Chris Porrino will become chief counsel, after two years as director of the Division of Law in the Attorney General's Office.

Also Thursday, the Republican Governors Association said it had hired Christie campaign manager Bill Stepien as a consultant. Christie is RGA chairman for the next year.