TRENTON, N.J. — Governor Chris Christie’s administration sought to borrow hundreds of millions of dollars to renovate New Jersey’s deteriorating State House four months before the project was authorized, according to interviews and documents.

The move cut the public out the process, which a bipartisan group of state lawmakers described as ‘‘rigged.’’

The Christie administration put out a request for proposals for a finance company to sell bonds to rehab the dilapidated building in December and selected RBC Capital Markets in January, according to documents obtained by the Associated Press through a records request.

That was months before an April meeting of a joint legislative-executive branch committee that approved the project.

The Republican governor says that everything was done legally and has defended his handling of the sweeping project to renovate the executive wing of the building — part of which dates to the 18th century and has flaking paint, duct-taped skylights, and inadequate fire safety devices.

There is little prospect for stopping the project, which could end up costing nearly a half-billion dollars and has drawn concerns about transparency and a lawsuit from Democrats and Republicans.

A Superior Court judge ruled last month that the lawsuit was moot since the bonds to pay for the project had already been sold.