"I have made this decision in the best interest of the Fund, as it will expedite the selection process for my successor," Lagarde said Tuesday. Lagarde said her resignation will be effective on Sept. 12.
Lagarde took over the IMF in 2011 after her predecessor, Dominique Strauss-Kahn, was ensared in sexual assault allegations. As managing director, she coordinated large bailout loans for Greece in concert with the ECB and European Union.
She was nominated to be the first woman president of the ECB July 2 by the eurozone's 19 member governments. If her nomination is approved, Lagarde will replace Mario Draghi, who has pushed the ECB's benchmark interest rate to record lows near zero and has spent 2.6 trillion euros on European financial assets in an effort to boost growth and inflation.
Under Lagarde's leadership, the IMF has supported those efforts and warned against premature rate hikes.