Transportation giant Laidlaw Incorporated is facing a huge tax bill. An American judge has ruled that the Burlington, Ontario-based company owes $141 million US in back taxes.

The ruling deals with a Laidlaw subsidiary in the Netherlands, which provided financing for some of Laidlaw's U.S. operations.

The judge has disallowed deductions related to that financing, and ordered Laidlaw to pay $49.6 million US in taxes and interest of about $91.4 million US.

The announcement battered the company's stock price. Shares of Laidlaw dropped $2.05 or more than 11 per cent, to $15.70 in morning trading on the Toronto stock market. About 2.1 million shares were traded.