US chip maker Atmel has fired four executives, including its founder, chairman and chief executive officer, after an investigation into alleged misuse of corporate travel funds, the company said yesterday.

George Perlegos, who founded the company in 1984 in San Jose, California, was stripped of his numerous titles, including chairman and CEO, while his brother, Gust Perlegos, an executive vice president, was also released by the company.

The two Perlegos brothers have also been asked to resign from the board of directors.

In addition, Atmel dismissed its vice president and general consul, as well as the vice president of planning and information technology, the company said.

None of the four former executives could be reached immediately for comments. The company's stock rose 4.7 percent to the day the news was announced.

Steven Laub, a director at Atmel, took over as president and CEO, while David Sugishita, was appointed the new non-executive chairman of the board, and Tsung-Ching Wu was made the new executive vice president. The other positions remained unfilled.

The decision to release the four executives is unrelated to the start last month of an investigation into the timing of past stock options grants, Atmel said.

The company, which makes chips for smart cards, wireless VoIP (voice over Internet Protocol) handsets and a range of other devices, employs 8,000 people worldwide and had $1.68bn in sales last year.