Two ex-managers at Alstom Konstal — the firm's Polish subsidiary — and three former Warsaw municipal employees are suspected of links to three contracts for delivering 108 subway cars and 122 tramways to the Polish capital in 1998-2002, according to prosecutors.
Prosecutors in the western city of Wroclaw told AFP that French justice officials had been slow to cooperate in the investigation launched in 2008.
A spokesman for Alstom Konstal declined to comment on the ongoing case.
The US Justice Department announced last week that Alstom would plead guilty and pay a record $772.3-million (€635.2 million) penalty in a wide-ranging foreign bribery case.
Alstom admitted to bribing officials to win power and transportation projects from state-owned entities around the world, including the Bahamas, Egypt, Indonesia, Saudi Arabia and Taiwan.
Fresh corruption charges have also been brought against a British subsidiary of Alstom.
London's Serious Fraud Office has filed corruption charges against the unit and two employees in securing a contract for a power plant in Lithuania, according to court documents seen by AFP.
It was the second Alstom unit to face charges in Britain this year, after Britain's SFO in July launched proceedings against an Alstom unit over alleged corruption in India, Poland and Tunisia.