(Corrects figure in fourth paragraph to C$1.6 billion from C$1.6 million)
* Ontario lawsuit seeks C$50 bln in healthcare costs
* Splits liability among tobacco companies by market share
* Becomes the 3rd Canadian province to sue Big Tobacco (Adds details)
By Andrea Hopkins
TORONTO, Sept 29 (Reuters) - The Canadian province of Ontario said on Tuesday it has filed a lawsuit seeking C$50 billion ($45.9 billion) in damages from tobacco companies for healthcare costs incurred by taxpayers since 1955.
In doing so, Ontario became the third of Canada's 10
provinces to sue the country's tobacco manufacturers, all of
which are units of foreign tobacco makers, including Philip
Morris International Inc
The lawsuit by Ontario, Canada's most populous province, was planned under legislation passed by its Legislature earlier this year, and seeks damages for past and ongoing healthcare costs.
Ontario says tobacco use costs the province C$1.6 billion a year for healthcare and causes about 13,000 deaths annually. It said smoking is the province's No. 1 cause of illness and premature death.
The legislation allows Ontario to directly sue tobacco companies for alleged wrongdoing and allocates liability among tobacco companies by market share.
Two other provinces, British Columbia and New Brunswick, have already filed suit against the tobacco companies, and all but two provinces have created legislation to lay the groundwork to do so.
After years of battling lawsuits, Big Tobacco in 1998 agreed to pay U.S. states more than $200 billion to help pay for the costs of treating ailing smokers.
($1=$1.09 Canadian) (Additional reporting by Brad Dorfman in Chicago and Julie Crust in London) (Reporting by Frank McGurty and Andrea Hopkins; editing by Peter Galloway)