File photo: In this file photo taken on October 28, 2019, the logo of the Societe Generale bank is pictured, in Ouistreham, Normandy, northwestern France. AFP
Some 150 investigators conducted searches in Paris and the financial district La Defense, the financial prosecutor's office (PNF) said in a statement.
The raids follow five preliminary investigations that were opened in December 2021 in connection with suspected money laundering and aggravated suspected tax fraud related to dividend payments, the statement said.
The operation "required several months of preparation", the statement said, and involved 16 investigating magistrates and more than 150 financial investigators.
Prosecutors from Germany, where similar tax frauds came to light in recent years, were also involved in the raids, the statement added.
A spokesman for Societe Generale confirmed to AFP that the French bank was being searched by authorities, but he said he did not know the reason.
French rival BNP Paribas and its Exane unit, financial group Natixis and British banking giant HSBC are the other targets of the raids, according to Le Monde newspaper.
A group of European news outlets published an investigation dubbed the "CumEx-Files" into the tax fraud in 2018.
Its title referred to trading of shares with ("cum" in Latin) and without ("ex") dividends.
The amounts involved are suspected to have reached 140 billion euros ($151 billion) over a period of 20 years, the media group said in 2021.
Tuesday's raids stem from so-called "Cum-Cum" tax fraud.
"The fraud involves a foreign shareholder in a company listed in France temporarily transferring the shares he owns to a French banking institution, around the date the dividend is paid out," the PNF said.
The aim is "to avoid paying the tax applicable to the payment of this dividend," it added.
Banks are suspected of acting as intermediaries in the practice and even charging a commission to the investors taking part.
A German court in December sentenced lawyer Hanno Berger to eight years in prison over the "cum-ex" tax scam, convicting him of three counts of aggravated tax evasion.
The regional court found that the 72-year-old -- believed to be the original mastermind of the scheme -- helped arrange fraudulent transactions at German bank M.M. Warburg between 2007 and 2013 that cost Berlin's treasury 278 million euros.
In addition to the jail time, the court ordered 13.7 million euros ($14.8 million) of personal revenues from the scheme to be confiscated from Berger's accounts.
Berger only partially admitted wrongdoing during the proceedings, insisting that some of the transactions were legal at the time.