The grand jury dismissed a more serious felony charge of second-degree robbery, Erie County District Attorney Frank Sedita III said.
Kane, 20, and his cousin, James Kane, 21, were arrested Aug. 9 after 62-year-old cabbie Jan Radecki told police they attacked him when he said he didn't have 20 cents in change for the fare. James Kane was indicted on the same charges.
The cab driver had bruises and broken glasses.
At a U.S. Olympic hockey camp in suburban Chicago, Kane said he had not heard any details about the indictment and wanted to talk first with his lawyer.
"If the felony is dropped, that's obviously a positive step," Kane said. "The sooner it gets over, I think, the more everyone will be happy about it."
The Kanes earlier pleaded not guilty to the charges. They were indicted on charges of third-degree assault and theft of services, both misdemeanors, as well as harassment, a violation. Arraignment is scheduled for Thursday afternoon.
If convicted, the Kanes could get up to a year in jail.
Calls to Patrick Kane's lawyer, Paul Cambria, were not immediately returned.
"As is the practice in all criminal cases, the assigned prosecutor and defense counsel will discuss a possible resolution of the case short of trial," Sedita said in a statement.
A plea deal would be based on the victim's wishes, the severity of his injuries and other factors, Sedita said. But Kane's celebrity status "is not such a consideration," he said, adding, "Kane will not be prosecuted more leniently or more harshly because he is employed as a hockey player."
The cabbie has said he wants a public apology from the Kanes, not jail time, said his lawyer, Andrew LoTempio.
"I can't comment as to his point of view," Sedita told The Associated Press. "The name of the action is the People of the State of New York v. the Kanes, not Jan Radecki v. the Kanes.
"We often have domestic violence cases where victims do not want to go forward, but we go forward with it anyway. I'm not saying that's the case here but just to illustrate the point. Obviously, we take a victim's wishes into consideration all the time."
Kane, the No. 1 overall pick in the 2007 draft and the rookie of the year in 2008, had 25 goals and 45 assists last season, and his team has built a marketing campaign around him. He helped the Blackhawks advance to the Western Conference finals last season.