Apple Working With Ferrari, Volvo for On-Board Operating System

Apple Inc. is set to announce next week it's to add Ferrari and Volvo Car Corp to its list of car makers with which it's working to develop and install an on-board operating system, people familiar with the initiative said Saturday.

Apple's announcement will coincide with the opening of the annual motor show in Geneva, which the car industry often uses to show off concept cars and other upcoming technologies.

The car has...