WASHINGTON (Reuters) – Novartis’ generic drugs unit Sandoz has agreed to pay $195 million to reach a deferred prosecution agreement aimed at resolving antitrust charges, the Justice Department said on Monday.

The company was charged with rigging bids and fixing prices of more than $500 million worth of generic drugs between 2013-2015, said the department, which has been probing the generic drug industry for three years.

U.S. drug pricing has become a political issue in recent years amid complaints that some drugs, including medicines on the market for decades, have seen sharp price increases.

“Sandoz conspired for years with other manufacturers and their executives to raise prices for critical medications, and the Antitrust Division will continue its ongoing investigation to hold both individuals and corporations accountable,” said Makan Delrahim, head of the Justice Department’s Antitrust Division.

Three executives, including one from Sandoz, have pleaded guilty to being part of the scheme, and a fourth is awaiting trial. Two other companies have also been charged and settled last year, Kavod Pharmaceuticals and Heritage Pharmaceuticals.

“In reaching today’s resolution, we are not only resolving historical issues but also underscoring our commitment to continually improving our compliance and training programs,” Sandoz President Carol Lynch said in a statement. “We are disappointed that this misconduct occurred in the face of our clear antitrust compliance policies and multiple trainings.”

The drugs involved in the scheme included clobetasol and desonide, steroids used to treat skin conditions like eczema and psoriasis; nystatin triamcinolone, a combination antifungal and steroid; the high blood pressure combination medicine benazepril HCTZ; and tobramycin inhalation solution, used to treat people with cystic fibrosis who have a bacterial infection.

(Reporting by Diane Bartz; Editing by David Gregorio and Bill Berkrot)