New York Times News Service

WASHINGTON — Saying that safety practices at General Motors were “broken,” federal regulators on Friday imposed the biggest punishment they could on the automaker and condemned it over its failure to promptly report a defect that GM has linked to 13 deaths.

GM will pay a $35 million penalty — the maximum allowed, and the largest ever imposed on an automaker — and will be required to make wide-ranging changes to its safety practices that will be supervised by the government, another first for an automaker.

“What GM did was break the law,” Anthony Foxx, the secretary of transportation, said at a news conference.

The investigation found “deeply disturbing” evidence over how GM treated safety concerns, said David Friedman, who works under Foxx as head of the National Highway Traffic Safety Administration.

Friedman cited an internal presentation from 2008 that was used to train employees to obscure some problems.

Workers writing reports were encouraged to avoid using certain words and phrases with negative overtones, including “apocalyptic,” “dangerous,” “death trap, “potentially disfiguring,” “rolling sarcophagus” and “Corvair-like,” as well as more benign phrases like “safety” and “safety related.”

Under the consent order, GM must meet monthly with regulators for a year and provide a list of every safety-related issue under consideration by the company, as well as report on any new communications with dealers.

The company also agreed to improve information-sharing across its different units, make recall decisions more quickly and revise its analysis practices to improve the ability to identify safety issues.

Friedman said that the close oversight of GM by the safety agency — which itself is under investigation by lawmakers for failing to act on the problem — would last up to three years and would be thorough “to the point that the instant they see there’s a potential safety issue, they have to tell us about it.”

GM said it would work with regulators to improve its safety practices.

“We have learned a great deal from this recall,” Mary Barra, GM’s chief executive, said in a statement. “We will now focus on the goal of becoming an industry leader in safety. We will emerge from this situation a stronger company.”