In echoes of Australia and GE money, the New York State Supreme Court said Dell lured customers with advertisements offering "no interest" or "no payment" financing options, but its financing arm would charge higher rates.

Furthermore the court found that Dell and its affiliate Dell Financial Services also advertised special no-interest financing, but denied almost everyone those terms, often selling customers products without informing them that they didn't qualify for the special financing terms and then charged them interest rates as high as 30 per cent, the court said.

Dell said it strongly disagreed with the ruling, although it has not decided whether or not to appeal.

"We don't agree with this decision and will be defending our position vigorously. Our goal has been, and continues to be, to provide the best customer experience possible," the company said in a statement.

"We are confident that when the proceedings are finally completed the court will determine that only a relatively small number of customers have been affected," it said.