PARIS - International Monetary Fund (IMF) chief Christine Lagarde was placed on Wednesday under formal investigation for "negligence" in her handling of a scandal involving tycoon Bernard Tapie in 2008.

Lagarde, questioned since August 2011 for "complicity in forgery and embezzlement of public funds" in the Tapie case, said she has no plan to resign.

"I'll return to work in Washington as early as this afternoon," Lagarde told AFP.

The 58-year-old former lawyer stressed the court decision was "unfounded" and that she would file an appeal, according to the report.

In May 2013, the IMF director was named as "assisted witness," in the fraud investigation, which means there is a possibility for her to be charged later.

The investigation focuses on the decision made by Lagarde, who in 2008 as France's finance minister under Nicolar Sarkozy's administration, chose to order a panel of judges to settle by arbitration a legal dispute between businessman Tapie and the state-owned bank Credit Lyonnais over the mishandled sale of sports company Adidas in 1993.

The arbitration resulted in Tapie winning 285-million-euro (375. 74-million-dollar,1 euro = 1.318 US dollar) payment plus interest, totalling 400 million euros from Credit Lyonnais.