Zhang said the mistake occurred after Dell begun switching chips on certain laptop models but the sales brochures and order forms were not updated on time.

However Zhang Min, who was first to file his case in Shanghai, said in the China Daily that negotiations with the Texas-based group had proved futile.

"I tried to negotiate with Dell and simply asked them to change the CPU, but they said there was no difference between the two and it was unnecessary to change (it)," Zhang Min was quoted by the newspaper as saying.

"My lawyer sent them a letter demanding compensation which Dell chose to ingore, so we decided to sue."

Guo Zhongfang, one of the lawyers involved in the cases, said: "Dell has defrauded Chinese consumers and should be fined according to the law."

An online bulletin board set up by Dell users in China has registered 500 people so far, which could mean the number of lawsuits against the company will increase.