BOSTON (AP) Thousands of pages of federal audits in Boston’s Big Dig road construction project were made public Friday, April 11, when one of the contractors opted not to fight a judge’s ruling allowing their release.

The audits show that Parsons Brinckerhoff overbilled the state millions since 1991, although in some instances auditors also said the company should be allowed to bill additional amounts for its work. The documents also show that Parsons "strongly disagreed" with some of the accounting methods used in the audits.

Audits of Bechtel Corp. found smaller overbillings, and that Bechtel actually underbilled the state by about $1.4 million from 1993 to 1995.

Parsons and Bechtel are part of a private joint venture overseeing the massive $14.6-billion highway project that will bury part of Interstate 93 beneath downtown Boston and connect the Massachusetts Turnpike with Logan International Airport. It is among the largest public works projects in U.S. history.

The audits were commissioned by the state and conducted by the Federal Defense Contract Audit Agency.

The audits, among other findings, recommended that Parsons be asked to repay $3.7 million from a 1995 contract, while Bechtel overbilled the state $2.4 million in 1991. Bechtel agreed to remove certain expenses from its billing, including entertainment, auto expenses and club dues, according to the audits.

Massachusetts Turnpike Chairman Matthew Amorello said that the agency is trying to recover any money it is owed. The audit findings have gone to mediation before a federal appeals board that typically settles disputes involving defense contractors.

"We have been using the audit findings to secure back any money owed to the taxpayers," Amorello said. "The difference between what they think and what we think is pretty vast."

Turnpike officials said its analysis of the audits showed that Parsons overbilled a total of $31 million from 1991 to 1998. A spokesman for the contractors did not immediately return a phone call Friday.

Bechtel had asked a judge to block release of the documents, which are on file with the state. A judge denied the request Thursday, April 10. Bechtel, which argued that the audits contained trade secrets and proprietary information, opted not to appeal the ruling.

Lawyers for The Boston Globe and The Associated Press filed court papers on Wednesday, April 9 seeking the audits.

Today's top stories

Blalock Crews Build TDOT's $67M Newport Bypass

New Bridges Part of Iowa's $114M Madison Avenue Project

Eagle Bridge Co. Works On Final Leg of U.S. 35 Upgrade

SAKAI Achieves Record Sales, Production

Takeuchi Recognizes Top Dealers at 2024 Dealer Summit

Equip Expo's Summer Giveaway Offers a Chance for Lifetime Trade Show Registration, Gift Card, Hotel Stay

Tennessee's Pugmill Systems LLC Expands Its Product Offerings to Include Concrete Plants

ASCENDUM Machinery Opens New Savannah, Ga., Facility