The SEC has been investigating the company's sales reporting practices before the company changed them in July 2016, the automaker has said.
The suit said Bigland's candor with U.S. investigators and "unwillingness to act as a scapegoat for defendants' 30-year practice which predated him" resulted in the company retaliating "less than two months later by withholding his compensation."
Fiat Chrysler said in a statement Bigland's incentive pay was subject to a board committee determination and his "eligibility for his award remains subject to that determination and completion of a board-level evaluation of issues that are the subject to governmental investigations."
The company said it would be inappropriate to comment further.
Fiat Chrysler in July 2016 revised more than five years of monthly U.S. vehicle sales figures to reflect a new reporting method and disclosed that the U.S. Justice Department and SEC were investigating.
The company had boasted of carving out year-over-year sales gains every month since April 2010, for a 75-month streak through June 2016. But it said that winning streak would have ended in 2013 under the revised reporting methodology.
The company said in its 2018 annual report it continued to cooperate but the investigations' "outcome is uncertain and cannot be predicted at this time." In April, Fiat Chrysler settled a sales reporting lawsuit by an Illinois dealership group.
Bigland in January 2019 submitted a white paper to the SEC on Fiat Chrysler's monthly sales reporting method before July 2016 and gave a draft to Fiat Chrysler.
Bigland, who has been head of Fiat Chrysler's U.S. sales since 2011 and also is head of the Ram brand and its Canada operations, said in his suit he "did not invent or manipulate (Fiat Chrysler's) monthly sales reporting methodology" and that the "monthly sales reports had no appreciable impact on investors."
His white paper said the methodology had been in place since the late 1980s and widely known throughout the company including by Sergio Marchionne, who was chief executive until his death in July 2018, and other executives.
Deborah Gordon, a lawyer for Bigland, said her client's performance at Fiat Chrysler "has been outstanding" and he remains on the job.
Bigland's suit also said Fiat Chrysler was angry that Bigland sold shares in the company. The suit said Fiat Chrysler has refused to award him shares in May and special dividends on those shares would amount to $1.8 million.
Bigland's suit was filed in late May in a state court in Michigan and moved by Fiat Chrysler to U.S. District Court in Detroit on Wednesday.
(Reporting by David Shepardson; Editing by Tom Brown)
By David Shepardson
