million shares, representing a 23.7 percent stake, in Bermuda-registered ADT Ltd., a leading provider of electronic security services and vehicle auction services.

Laidlaw said any sale would depend on factors including its ability to sell the securities at "satisfactory'' price levels and its continuing evaluation of ADT's business, Bloomberg Business News reported, citing a story in yesterday's Wall Street Journal.

Earlier this month, ADT, with head offices in Florida, reported third quarter profit of $19.3 million, down from the $23 million for the same period a year earlier.

On November 2, Laidlaw said its solid waste management and recycling unit, Laidlaw Waste Systems, agreed to acquire the solid waste collection and transfer business of Hamilton-based Philip Environmental Inc. in Montreal.

Listed on the New York, Toronto and Montreal exchanges, Laidlaw is a major provider of environmental management transportation services to municipalities and industries throughout North America.