Eric Woerth, formerly Sarkozy's budget minister and treasurer of his UMP party, was charged with "corruption, abuse of trust, money laundering... and receiving (illicit funds)", prosecutors said in a statement.
The new charges came after the second day of Worth's interrogation by judges in the southwestern city of Bordeaux about the alleged influence peddling and alleged illegal campaign donations by L'Oreal heiress Bettencourt.
The influence peddling charges are likely to relate to allegations Woerth secured the Legion of Honour, France's highest award, for Bettencourt's financial manager, Patrice de Maistre, after he secured a job for Woerth's wife to help manage the heiress's fortune.
They are punishable by up to 10 years in prison and a 150,000 euro fine.
Bettencourt, France's richest woman, is at the centre of a series of long-standing, overlapping legal inquiries.
They include one into claims she showered leading right-wing figures with envelopes stuffed with undeclared campaign donations in the run-up to Sarkozy's election in 2007.
The Woerth case is one of several corruption investigations plaguing Sarkozy as he prepares for a tough re-election fight against Socialist flag-bearer Francois Hollande in a two-round vote in April and May.
Sarkozy, who as president is immune from criminal prosecution, has fiercely denied any personal wrongdoing.
Woerth left the government in 2010 and in 2011 police carried out searches of his home and the UMP's offices in connection with the case.
He has strongly denied the allegations.