The US health authority, the FDA, is delaying the approval of new varieties of white, tobacco-free snus.
The reason, Reuters sources say, is concern that young people will be drawn to increased nicotine use; the FDA has not commented.
On Wednesday, several tobacco companies fell in trading on the New York Stock Exchange.
American Philip Morris, which owns the former Swedish company Swedish Match, fell 4.8 percent; British American Tobacco fell 1 percent; and Turning Point Brands plunged 14.5 percent.
After pressure from the White House, the FDA last year introduced a fast track for approving new varieties of white snus.
