GREENVILLE, Miss. (AP) _ A trial began this week to determine whether a man's 50-pack-a-year Pall Mall habit killed him.

Anderson Smith Jr.'s children sued The American Tobacco Co., makers of Pall Malls, and the now-defunct New Deal Tobacco and Candy Co. Inc., local distributors of the cigarettes, in 1987, saying the cigarettes the companies made and distributed killed their father. Testimony began Wednesday.

Smith, a disabled military veteran who smoke unfiltered Pall Malls for about 40 years, died in 1986 at age 63.

The tobacco companies said he died three days after exploratory surgery on his bladder and prostate was stopped due to excessive bleeding.

Smith's death certificate lists cancer as the cause of death. The tobacco companies cite Smith's 43-year history of urinary tract infections from venereal disease as a major contributor to his death, which they said most likely was caused by a blood clot.

Circuit Judge Eugene Bogen already has ruled that cigarettes cause cancer and death. A jury must decide if the cause of Smith's death was lung cancer and emphysema, as the lawsuit said, and if Pall Malls were the cause of the diseases.

''Our proof will show very clearly Mr. Smith contracted two lung diseases from smoking Pall Mall cigarettes,'' lawyer Don Barrett said in his opening statement.

He represents Smith's adult children, Jeanette Wilks and Jessie Willie Bell. They are suing the tobacco companies for $17 million. Damages would be determined after the jury's verdict on the cause of death.

''Death is never simple,'' lawyer James Upshaw, who represents American Tobacco of Stamford, Conn., told the jury in his opening statement.

''He didn't die from cancer. He died with it, not from it. Death certificates are notoriously inaccurate,'' Upshaw said.