It took awhile, but Panasonic has announced that it will finally make Sanyo a wholly owned subsidiary.

The company said it plans to acquire the remaining 20 percent of Sanyo stock that it doesn't own through a "share exchange" with the company. As of March 28, Sanyo shares will be officially delisted from the Tokyo Stock Exchange, paving the way for Panasonic to acquire the remaining shares on April 1.

Panasonic first made its intentions to buy Sanyo known in December 2008. At that time, the company agreed to acquire Sanyo for $8.9 billion. However, it wasn't until a year later, after regulatory concerns were meted out, that Panasonic was finally able to gain control over Sanyo, acquiring just 50.2 percent of the company for approximately $4.59 billion.

Not content with just half the company, Panasonic completed its acquisition of another 30 percent of Sanyo back in October, bringing its stake to 80.77 percent.

Panasonic's intentions to fully own Sanyo are rooted in its desire to capitalize on the growing green market. Sanyo is a major player in the rechargeable-battery and solar-panel markets. In addition, the company was making a big push for the car battery market, saying earlier this year that it expects to own 40 percent of that space by 2021. By then, around 11 million vehicles are expected to feature hybrid batteries.