(Adds Lorillard comments, background about 1998 settlement)

By Julie Steenhuysen

CHICAGO, July 16 (Reuters) - Tobacco companies manipulate the amount of menthol in cigarettes to make those first few puffs more palatable to young smokers, U.S. researchers said on Wednesday in a finding that could fuel support for more tobacco regulation.

"Menthol stimulates the cooling receptors in the lung and oral pharynx," said Dr. Gregory Connolly of the Harvard School of Public Health. "It makes smoking easier."

The study, published in the American Journal of Public Health, comes as the U.S. Congress considers legislation that would give the Food and Drug Administration broad authority to regulate tobacco.

Representatives of tobacco companies R.J. Reynolds, Philip Morris and Lorillard disputed the findings.

"It would appear this report is simply an effort to push support for federal regulation of the tobacco industry, not a scientific review of the menthol category," said David Howard, a spokesman for R.J. Reynolds, a unit of Reynolds American Inc (RAI.N: Quote, Profile, Research) and maker of Camel and Kool cigarettes.

Lorillard Inc (LO.N: Quote, Profile, Research) spokesman Michael Robinson said in a statement: "The American public should view this report for what it is, a politically motivated lobbying tool."

Smoking is the biggest cause of preventable death in the United States, killing more than 400,000 people each year.