Takata Corp. has homed in on bids from Autoliv Inc. and Key Safety Systems Inc. as the air bag maker behind the biggest auto safety recall ever progresses toward a final round of negotiating a sale, according to people familiar with the matter.

The two bidders gained an edge because both have technical expertise in air bag systems and safety equipment and because carmakers view them as able to lower costs and improve the quality of Takata parts, said two of the people, who asked not to be identified. Takata is working to find a buyer and finalize its restructuring plan by year-end, the company said this month.

Takata had three other bidders make it to the most recent round of the sale process: private equity firm KKR & Co.; Bain & Co. and Daicel Corp. of Japan in a joint pitch; and auto-parts suppler Flex-N-Gate Corp. The sale process has been described as fluid, given the complex nature of Takata's litigation, and any of the bidders could come back. Flex-N-Gate has a record of integrating acquisitions and could still return with a winning bid, especially if there were antitrust concerns with another suitor, one of the people said.