Fiat Chrysler Chief Executive Mike Manley sold shares in the car maker for $3.46 million on May 28, the day after the announcement of a merger proposal to French rival Renault, a regulatory filing showed.
An FCA spokesman said Manley sold the shares to cover a personal expense. A filing by Dutch stock market regulator AFM showed Manley sold 250,000 shares at $13.85 each.
Shares in Fiat Chrysler lost 4.2 percent by 0726 GMT, underperforming a 2.6 percent drop in the European car sector driven by trade tensions. A Milan-based trader Manley's move was "not a good sign" and compounded the weakness in FCA's shares.