The former chief executive of a Northern Virginia defense contractor pleaded guilty to a federal charge of providing gratuities to a federal contracting official, and the company agreed to pay a $300,000 fine for its involvement in the bid-

rigging scheme, the Justice Department said Tuesday.

Harry Martin, who stepped down as the head of Intelligent Decisions last month, pleaded guilty to charges that he and other company officials paid illegal gratuities to an Army procurement official based in South Korea, spending more than $10,000 on dinners and golf outings and, in one case, agreeing to spend more than $30,000 on a Lexus ES350 for the official to use, according to the department.

In return, the company received lucrative contracts from the official, identified as Seon Lim, and preferential treatment on Army subcontracts worth up to $4 million.

“Although these violations occurred five years ago, Intelligent Decisions views any failure to conduct our business according to the strictest legal and ethical standards as a serious matter,” Joe Armstrong, the company’s new chief executive, said in a statement about Martin’s departure.

A spokesperson for the company said Intelligent Decisions did not have anything to add to Tuesday’s announcement.

The Ashburn contractor is a private company that provides information technology services such as cybersecurity, cloud services and simulation software to government agencies. The company’s clients include the Justice Department, the Office of Personnel Management, and the Army, among others.

Martin is the 20th person to plead guilty in a years-long investigation into bribery and bid-

rigging schemes, the department said.

Lim allegedly received more than $490,000 in benefits from Intelligent Decisions and other contractors, including Chantilly, Va.-based security services company Nova Datacom and a South Korean corporation, according to federal officials. Lim pleaded guilty to bribery and two other federal offenses and is set to serve a four-year prison term, the government said.

Nova was at the center of the investigation that revealed a network of corrupt officials and contractors. The alleged ringleader, a bureaucrat named Kerry Khan, was sentenced to nearly 20 years in prison last summer.

Martin, who served as Intelligent Decisions’ chief executive since 1988, is set to be sentenced March 20, officials said.