The bank, which was already under investigation for illegal solicitation of customers in France, will now have to pay a total biil of 1.1 billion euros ($1.5 billion), the source told AFP.
UBS's Swiss business is suspected of illegally canvassing French customers and setting up dual accounts to hide the movement of capital into Switzerland.
The judicial source said the charges relate to money kept in accounts in Switzerland between 2004 and 2012.
A probe was launched after former UBS employees blew the whistle.
The ACP, the Bank of France's regulatory arm, had been alerted to the undeclared accounts between 2002 and 2007.
According to judicial sources, the new bail is equivalent to 42.6 percent of USB's after-tax profits last year and 2.8 percent of shareholder funds.
The move by Paris comes amid a global clampdown on tax evasion by authorities around the world.
This week Credit Suisse said it lost 700 million francs ($775 million) in the second quarter of the year after paying a $2.6 billion fine for tax evasion to the US.
On Monday, the OECD said countries had identified an estimated 37 billion euros of hidden taxes through voluntary disclosure by more than half a million taxpayers in recent years.