Panasonic Corp.'s plans to take over rival Sanyo Electric Co. would create the world's second-largest electronics maker. But Panasonic already has plenty of gadgets. Instead, the crown jewels Panasonic wants from Sanyo are green.

The ability to acquire Sanyo's two green-energy pillars, solar-cell technology and rechargeable batteries, are what drove Panasonic to announce this month it would negotiate a deal with Sanyo's main stockholders, Goldman Sachs Inc., Daiwa Securities SMBC and Sumitomo Mitsui Banking Co.

Analysts expect the price to be ¥500 billion to ¥850 billion.