The Greek government said it will take legal action against Siemens for allegedly bribing officials.
It follows an 11-month parliamentary investigation that estimated the cost to Greek taxpayers of the alleged bribery at 2bn euros ($2.7bn, £1.7bn)
The bribery allegedly took place during 1997-2002 and affected telecoms contracts as well as security prior to the 2004 Athens Olympics.
A Socialist ex-minister admitted his involvement in one bribe last year.
The former Transport Minister, Tassos Mantelis, told the investigating committee he had accepted the equivalent of 100,000 euros (£85,400, $136,700) in 1998.
Socialist politicians being investigated cannot be prosecuted due to the statute of limitation.
The investigating committee is expected shortly to name other ministers accused of accepting bribes.
The Greek action against the German firm follows the settlement in 2008 of other unrelated bribery accusations against the company in the US and Germany, which resulted in it paying out 1bn euros in penalties.
"Greece will seek compensation for the damage it has suffered from the corrupt practices that have been used by your company in the past," wrote investment minister Haris Pamboukis in a letter to the German company's Greek subsidiary, Siemens Hellas.
Joern Roggenbuck, a spokesman for Siemens AG, said the German parent company "has done everything humanly possible to shed light on the past dealings and has always fully cooperated with the authorities".