The corporate turnaround fund Innovation Network Corp. of Japan is encouraging Sony Corp., NEC Corp. and Nissan Motor Co. to merge their lithium-ion battery businesses in the face of intensifying international competition, sources said Friday.

The state-backed fund and the firms may reach a deal in fiscal 2013, with the fund investing in the merged entity, they said.

Automotive Energy Supply Corp., the Nissan-NEC venture that makes lithium-ion batteries for vehicles, is being encouraged to take a majority stake in Sony's battery unit, they said.

Sony Energy Devices Corp. makes batteries for phones and computers. Sony wants to sell it because competition from South Korea is too strong. The aim of the plan is to prevent foreign firms from acquiring key technologies from the coveted Sony unit, but the sources said the deal remains uncertain.