Shares of Mississauga-based auto insurer Kingsway Financial Services plunged 42 per cent Tuesday.

The price fell $1.24 to $1.70 on a volume of more than six million shares after the Pennsylvania Department of Insurance sought to reverse the company's donation of its indirect interest in Lincoln General Insurance Co. to a charity.

Kingsway Financial 3-month chartKingsway Financial 3-month chart

Kingsway announced last month it planned to shed the unit by donating all of the stock to 20 U.S. charities.

But the Pennsylvania Department of Insurance announced Monday it planned to pursue legal action to unwind the donations because it did not approve the Oct. 19 deal. The department contends the change in control without approval violates Pennsylvania law.

York, Pa.-based Lincoln lost $95.5 million in its latest quarter. Its primary business was providing insurance to the trucking industry.

Kingsway insisted in a statement that the department "has no legal basis for demanding the unwinding of the donations."

(With files from Canadian Press)