More than $100 million in city rail transit contracts will be the subject of an audit starting next month.

The examination was on the city auditor's fiscal 2009 schedule released yesterday. The decision follows a March request for the audit by five council members, said City Auditor Leslie Tanaka.

The audit will probe contracts and expenditures, though the exact scope has yet to be determined, Tanaka said.

"Obviously everybody wants to know how the money is being spent," he said.

So far the city has awarded $107.7 million in elevated commuter rail contracts. Most of that money — $86 million — is going to New York-based consultant Parsons Brinckerhoff over a 2 1/2-year period. The firm also received an additional $10.2 million to work on an earlier phase of the project.

The total project is expected to cost $3.7 billion. Mayor Mufi Hannemann wants to break ground in December of next year with the 20-mile system opening in phases between 2012 and 2018.

So far the largest subcontractor of the Parsons Brinckerhoff contract is R.M. Towill Corp., which has been paid $4.9 million, according to city records. SSFM International was next with $1.88 million, followed by ControlPoint Surveying with $1.85 million.

The state and the city of Honolulu are raising money to pay for the project via a 15-year increase in the state's general excise tax on O'ahu from 4.166 percent to 4.712 percent. The state began collecting the half-percentage-point general excise tax surcharge in January 2007 and $211 million was raised in the first 16 months, according to state tax department records.

Tanaka said the audit would begin next month and take eight to nine months to complete.

"We haven't gone in yet so it's hard to estimate exactly," he said.

Hannemann has said he thinks such a probe is premature.

The five council members who called for the audit were: Barbara Marshall, Romy Cachola, Donovan Dela Cruz, Charles Djou and Ann Kobayashi. The group called for more transparency and accountability over the transit project, but did not allege any malfeasance.

Dela Cruz yesterday supported the decision to audit the rail project.

"There may be something to it (or) there may not be," he said. "If the audit clears it, then at least the public can have confidence in the project."