July 3 (Reuters) - General Motors ( GM ) will pay a

$145.8 million penalty after a U.S. government investigation

found excess emissions from approximately 5.9 million GM

vehicles, government agencies said on Wednesday.

The Environmental Protection Agency said GM has agreed to

give up approximately 50 million metric tons in carbon

allowances after the multi-year investigation found vehicles

from the 2012-2018 model years were emitting more than 10%

higher carbon dioxide on average than GM's initial compliance

reports claimed.

The National Highway Traffic Safety Administration

separately said GM will pay a $145.8 million penalty for fuel

economy compliance issues and cancel more than 30.6 million fuel

economy credits for the 2008-2010 model years to resolve the

issues identified by EPA's light-duty vehicle in-use testing

program.

Reuters was first in reporting the settlement, citing

sources.

In a statement, GM said it "has at all times complied

with and adhered to all applicable laws and regulations in the

certification and in-use testing of the vehicles in-question"

but added it believes "this is the best course of action to

swiftly resolve outstanding issues with the federal government

regarding this matter."

Unlike the 2015 Volkswagen diesel emissions

case, the EPA is not alleging GM used a defeat device to

intentionally reduce emissions in testing.

The EPA is not seeking a recall of the GM vehicles that

generated excess emissions.

"EPA's vehicle standards depend on strong oversight in order

to deliver public health benefits in the real world," EPA

Administrator Michael Regan said in a statement. "Our

investigation has achieved accountability and upholds an

important program that's reducing air pollution and protecting

communities across the country."

The vehicles include 4.6 million 2012-2018 full size pickups

and SUVs and approximately 1.3 million 2012-2018 midsize SUVs.

In June 2023, NHTSA said GM paid $128.2 million in fuel

economy penalties for not meeting requirements for 2016 and

2017. GM, which sells Chevrolet, Buick, GMC and Cadillac

vehicles in the United States, had not previously paid a fine in

the 40-year-old history of the fuel economy program. It had

initially planned to use credits to meet its compliance

shortfall but opted to pay penalties, NHTSA said.

Last year, NHTSA had proposed hiking fuel economy standards

from 2027 through 2032 that it estimated would cost GM $6.5

billion over the period. Under the final rule issued last month

NHTSA said GM could face $906 million in penalties through 2031.