Chipmaker Qualcomm Inc (QCOM.O) said on Thursday it had offered to buy Swedish auto parts maker Veoneer Inc (VNE.N) for $4.6 billion, an 18.4% premium to a bid in July by Canada's Magna International Inc (MG.TO) that was accepted by Veoneer's board.

U.S.-listed shares of Veoneer, spun off in 2018 from air bag and seatbelt maker Autoliv (ALV.N), rose 28% as the stage was set for a bidding war.

Veoneer said its board of directors would "evaluate the proposal from Qualcomm consistent with its legal duties and the terms of the Magna merger agreement."

Magna did not make any immediate comment.

Demand has been on the rise for advanced driver assistance systems, known in the industry as ADAS, that add features ranging from collision warning to parking assist. Some systems collect data from cameras and radar to monitor surroundings, interpret the situation and take action.