WASHINGTON — Supreme Court Justice Samuel Alito took part in a case over curse words on television involving ABC Inc. and other networks even though he owned stock in ABC’s parent, Walt Disney Co., at the time.

Alito said Tuesday that he owned around $2,000 in Disney stock when the court heard the case FCC v. Fox Television Stations in late 2008. ABC and the other networks also were parties to the case.

Alito said his participation was an oversight. He said aides who routinely check for conflicts in high court cases missed the Disney connection when they looked at the Fox case, even though ABC’s brief clearly disclosed Disney’s ownership.

In any event, Alito voted with the majority, against ABC’s interests. The case came out 5-4, suggesting that Alito’s participation directly affected the outcome in which the court threw out an appeals court ruling favorable to the networks.

The FCC’s policing of the airwaves is again heading to the high court, also following a ruling for the networks. This time, Alito can take part without any worry as he sold his Disney stock last year.

The justice thinks he lost a few dollars on the deal. The issue arises now because the stock sale was disclosed in Alito’s annual financial report that was released Friday.

The federal conflict of interest law for judges says they should not hear a case if they have a financial interest, however small, in a party. The statute does not provide a penalty for violation.

Stephen Gillers, an ethics expert at New York University, said simply that Alito “should not have participated.”

In an interview with The Associated Press, Alito conceded as much. “It’s a mistake,” he said.

Alito owned the Disney shares for many years, after his mother bought $1,000 worth of stock for each of his two children. “My mother decided it would be a cool thing for them to have the actual certificates,” Alito said.

He finally made the sale in February 2010.