San Francisco CNN Business  — 

A top executive at Fiat Chrysler is suing the automaker for allegedly retaliating against him for cooperating with an investigation into the company by the Securities and Exchange Commission.

Reid Bigland, head of US sales, claims in the suit filed Wednesday that Fiat Chrysler (FCAU) withheld about 90% of his pay upon learning that he took part in a government probe into its sales-reporting practices.

Bigland also claims the pay cut was in retaliation for selling shares in the company in 2018.

Fiat Chrysler declined to comment Wednesday.

The suit alleges that when Fiat Chrysler cut Bigland’s pay it violated Michigan’s Whistleblowers’ Protection Act, which prohibits retaliation against employees “participate in hearings, investigations, legislative inquiries, or court actions.”

In October 2018, Bigland was named global head of Fiat Chrysler’s Ram brand — a brand that represents 29% of Fiat Chrysler’s US sales so far this year. He’s been in charge of US sales since June 2011 and has been an employee of what is now Fiat Chrysler for 22 years.

Bigland is still an employee of Fiat Chrysler, according to his attorney Deborah Gordon.

“Our complaint speaks for itself,” Gordon told CNN Business. “My client’s performance has been excellent and there’s no performance-based reason for them to withhold his pay, bonus and shares payout.”

The SEC investigation was launched in about May 2017, according to the lawsuit. Bigland submitted a white paper on Fiat Chrysler’s reporting practices in January 2019.

The SEC did not immediately respond to a request for comment about the investigation’s status.

Chris Isidore contributed to this report.