General Motors Co said a new report of 303 deaths in 1.6 million recalled GM cars is based on "raw data."

GM said new research on crash deaths in the Chevrolet Cobalt and Saturn Ion by U.S. watchdog group Center for Auto Safety lacks "rigorous analysis."

GM said its investigation into the massive ignition switch recall and the impact of the defective switch is "ongoing."

(Reporting by Paul Lienert in Detroit; Editing by Eric Walsh)