CHICAGO (Reuters) - CVS Health Corp said on Thursday its decision to stop selling tobacco products last year led to a 1 percent decrease in cigarette sales in some states where the drugstore chain has a sizeable presence.

The September 2014 decision hurt sales, with general merchandise revenue at CVS pharmacies open at least a year falling 7.8 percent in the second quarter from a year earlier, the company said.

However, CVS said it benefited in others ways. In the eight months since the decision, nicotine patch purchases rose 4 percent from a year earlier in the 26 states where it had a market share of 15 percent or greater. The company also said the average number of visits to its retail clinics for smoking cessation counseling nearly doubled.

The 1 percent reduction in sales of cigarette packs occurred in 13 of the states where CVS's market share was at least 15 percent. The company said the decline equated to the average smoker in those states buying five fewer packs of cigarettes, or a total of 95 million.

The company estimated it held 1.5 percent to 2 percent of the U.S. tobacco market before it stopped selling the products, which accounted for about $2 billion in annual sales.

For the analysis, CVS said it compared cigarette pack purchases in markets where it had a presence with those where it did not. Researchers looked at sales in drug, food, big box, dollar, convenience and gas station retailers.

Chief Medical Officer Troyen Brennan said many people thought that smokers would go elsewhere to buy cigarettes once the chain stopped selling them.

"The data shows that our decision to not sell cigarettes did have an impact," he said.

CVS has 7,800 retail pharmacies and is the second-largest manager of prescription-drug benefits in the United States.

(Reporting by Nandita Bose in Chicago; Editing by Lisa Von Ahn)