Irish drug firm Elan Corp Plc voluntarily dismissed its U.S. lawsuit against Royalty Pharma , the U.S. investment firm which increased its offer to take over Elan last week, a court filing showed on Monday.

In a filing in U.S. District Court in Manhattan, Elan said it was dismissing the lawsuit with prejudice, meaning it cannot refile it. It gave no reason for dropping the case. A hearing had been set for Tuesday.

Elan won temporary relief from the court last week stopping Royalty from closing its tender offer after it argued that the disclosures in Royalty's bid were "materially inadequate." Royalty raised its hostile bid for Elan to a potential $8 billion on Friday.

(Reporting by Nate Raymond, writing by Padraic Halpin in Dublin; Editing by Gerald E. McCormick)