(Reuters) - The chief executive of Delphi Automotive (>> Delphi Automotive PLC), the auto supplier that supplied the defective switch to General Motors Co (>> General Motors Company) that has been linked to at least 13 deaths, said on Thursday that the automaker was responsible for approving the faulty part design.

Rodney O'Neal, testifying in front of the U.S. Congress, said his company made "the switch that GM approved and wanted.

"GM knowingly approved a final design that included less torque than the original target," he said in prepared written testimony he will make to members of a Senate subcommittee. "In our view, that approval established the final specification."

So far, GM has attributed 13 deaths and 54 crashes to the specific defect, in which the ignition switch can slip from the "run" to the "accessory" position, causing the engine to stall, air bags to not deploy, and a loss of power brakes and power steering.

O'Neal said Delphi has four production lines running to make ignition switches to replace the faulty parts that have been recalled by GM. He said Delphi has shipped more than one million new switches and is on track to deliver more than two million by the end of August.

(Reporting by Ben Klayman in Detroit; Editing by Bernadette Baum)

Stocks treated in this article : General Motors Company, Delphi Automotive PLC