WASHINGTON (CNN) -- U.S. Secretary of Commerce John Bryson stepped down Thursday, telling President Barack Obama in a letter of resignation that a recent seizure could be a distraction from doing his job.
"I have concluded that the seizure I suffered on June 9th could be a distraction from my performance as secretary and that our country would be better served by a change of leadership of the department," Bryson's letter said.
Bryson, 68, had been on a medical leave of absence since his involvement in two auto accidents in California that his office indicated were linked to the seizure.
The White House said Obama will meet with Bryson in the Oval Office later Thursday to thank him for his service as commerce secretary.
A statement by Obama praised Bryson's efforts to boost U.S. exports as commerce secretary and said Bryson has agreed to serve as a member of the president's Export Council.
Bryson's deputy, Rebecca Blank, will continue to serve as acting secretary, Obama's statement said. Police said Bryson was found unconscious at the wheel of his car after the two accidents this month.
Bryson was issued a citation at an area hospital where he received treatment, said Lt. Ariel Duran of the San Gabriel Police Department. Authorities must still decide whether to formally file charges.
Bryson voluntarily took a breathalyzer test that detected no alcohol use, the Los Angeles Sheriff's Department confirmed.
According to a Commerce official, Bryson was on personal time with no security detail when the accidents occurred and was driving his own vehicle. The official, who spoke to CNN on condition of not being identified, said Bryson was given medication to treat the seizure.
Bryson, who was driving a Lexus, rear-ended a Buick occupied by three men that was stopped at a railroad crossing in San Gabriel, said a police statement.
"Bryson spoke with the males, then left the scene, hitting the same car again as he left," the statement said.
The men in the Buick followed Bryson while calling 911 to report the accident, it said. Bryson drove to the neighboring city of Rosemead, where he hit a second car, according to authorities. Police then found him unconscious in his vehicle.
Two of the three men in the Buick were treated for minor injuries, according to police. Obama nominated Bryson to succeed Gary Locke as commerce secretary in May 2011. Bryson's Senate confirmation was delayed by Republican opposition. It came in October, and he became the 37th secretary of commerce.
A graduate of Stanford University and Yale Law School, Bryson served as chairman of the California utility company Edison International from 1990 until 2008. Before that, he was a co-founder of the Natural Resources Defense Council, a leading environmental group that strongly endorsed Bryson's nomination last year.