Siemens has said it will appeal a fine for illegally fixing prices in a cartel, which it led.

The European Commission Wednesday imposed the €418.7 million (£275.8m) fine for Siemens' involvement in a cartel fixing prices in the gas-isolated switchgear systems (GIS) market. Eleven companies were fined a total of €750.7 million with Siemens being fined the most for its cartel leadership activities.

However, while Siemens has stated it is appealing, it is only questioning the size of the fine rather than the offence itself.

A statement from the company said: "Price fixing in the GIS segment took place only in a few projects in the European economic area and only in the period between October 2002 and April 2004." It denied the blanket accusation of the Commission that it participated in a cartel in the European GIS market between 1988 and 2004, saying: "Internal investigations indicate that three Siemens PTD employees fixed prices between October 2002 and April 2004. These employees were suspended immediately after accusations became known and no longer work for Siemens."

Siemens acquired VA Tech in 2005 and assumed financial responsibility for it, including accepting any legal consequences resulting from any past anti-trust violations. This Austrian subsidiary accounted for €22.1 million of its penalty.

The Commission stated it had increased Siemens' basic fine by half, to the second-highest cartel fine ever imposed by the EU, as Siemens had the leading role. Siemens argues the fines are disproportionate.

Siemens is also presently undergoing embezzlement, bribery and fraud investigations in its fixed line telephony unit. Sixty employees have been questioned and several former executives arrested. The current Siemens chairman, in charge during the criminal activity periods, is under pressure to resign.

Chief executive Klaus Kleinfeld, just two years in the job, finds his company reeling from the BenQ offload, the delay of a Nokia joint-venture, and not one but two examples of corruption within its senior ranks. Although he has moved to add multiple effective external legal oversight to Siemens' affairs it now looks as if the most senior figure imaginable needs to be jettisoned if Siemen's good name is to be salvaged. That means Dr. Heinrich Pierer, chairman of the supervisory board.

Pierer was chief executive during the period of the alleged embezzlement and fraud, also for the GIS cartel era, and has so-far resisted shareholder calls to go. The company's annual general meeting takes place on Thursday.