A construction company whose projects included the stadium where the New York Mets play and the Sept. 11 Memorial agreed to pay up to $56 million in penalties and restitution after admitting a decade-long fraud that included routinely overcharging customers and ignoring minority hiring mandates, authorities announced Tuesday.

A deferred prosecution agreement in U.S. District Court in Brooklyn described the penalty and restitution to be paid by Lend Lease U.S. Construction, a division of an international construction company that employed more than 1,000 workers during the 10-year stretch from 1999 through 2009.

FBI Assistant Director-in-Charge Janice K. Fedarcyk said the deal capped a three-year investigation "into a systemic pattern of audacious fraud by one of the world's largest construction firms."

U.S. Attorney Loretta E. Lynch said the company "deceived their customers and stole taxpayer dollars" while abusing a program designed to benefit and train minority contractors.

"The defense of 'everyone does it' will not be a shield against law enforcement," she said.

In court papers, prosecutors described how the company routinely overbilled clients including federal, state and local government contracting agencies. The government said James Abadie, who formerly led the company's New York office, pleaded guilty Tuesday to conspiring to commit mail and wire fraud for overbilling Bovis' clients for more than a decade. Abadie, 55, faces up to 20 years in prison.

The company regularly added up to two hours of unworked overtime to timesheets for labor foremen and charged customers for weeks when foremen were on vacation or out sick, court papers said.

The government said the company also duped the states of New York and New Jersey into believing it had complied with programs designed to boost the participation of small construction companies and companies owned by women or minorities on public construction projects when it had not.

Although New Jersey eliminated its minority and women-owned portion of its program in 2003, obligations incorporated into contracts for public construction projects remained intact, court papers said.

As an example of how minority hiring requirements were dodged, prosecutors described an instance in which Lend Lease U.S. Construction falsely claimed that a company certified as a minority hiring unit would perform 100 percent of the general contract work on construction at the Bronx Criminal Courthouse.

In reality, Lend Lease U.S. Construction performed most of the work itself by directly managing the union, the government said. It said the company placed many of its long-term union employees on the minority-hiring compliant company's payroll, hired other workers and relegated the smaller company's role to providing paychecks for work performed by or at the direction of Lend Lease U.S. Construction employees.

In a statement, the company said it has fully and extensively cooperated in the probe since 2009.

"We accept responsibility for what happened in the past and have agreed to continue to make restitution to the affected clients," said Robert McNamara, chief executive officer of Lend Lease Americas region.

The company was formerly known as Bovis Lend Lease LMB Inc. or Bovis. It was still known as Bovis when a fatal fire occurred during its demolition of the former Deutsche Bank building in lower Manhattan.

Other projects on which it worked included the federal courthouse in Brooklyn, the U.S. Post Office and U.S. Bankruptcy Court in Brooklyn, Grand Central Terminal in Manhattan and various schools in New Jersey's Abbott Districts, where authorities say the company also acted fraudulently to avoid complying with minority hiring laws.

The deferred prosecution agreement spares the company from three counts of conspiracy to commit mail and wire fraud if it carries out its promises over the next two years.

The company has pledged to pay the $40.5 million penalty, along with restitution of more than $15 million to victims of the overbilling scheme and to comply in the future with all federal and state criminal laws. It has already paid the city of New York $5 million, $4 million of which is credited against the $40.5 million penalty.

The company also acknowledged in the deal that it has fired or forced resignations of officers and employees responsible for the misdeeds and reduced the responsibilities of others involved in the misconduct.

The government said it permitted the company to avoid criminal prosecution because of its extensive cooperation, its acceptance of responsibility, remedial actions it took voluntarily and its assurances that it will be a model of integrity in the construction industry in New York.