Updates to this story
The deal, which will see Sony pay out an estimated $602 million (50 billion yen), will allow the company to double output capacity for image sensors used in smartphones and other devices.
Sony sold the plant, which it used for making cell microprocessors for products such as the PlayStation 3, to Toshiba in 2008. Toshiba made good use of it using it with making chips - as a result it also had to modify lines at the plant so it could churn out CMOS (complementary metal-oxide semiconductor) sensors.
Sony will now take advantage of the modifications to try and strengthening its CMOS sensor business, according to Nikkei.
The deal between the two will mean Sony saves some of its dosh as buying an existing facility is much cheaper than constructing a new plant. Sony is thought to be considering expanding the plant as well as getting a helping hand from subsidies from the Ministry of Economy, Trade and Industry.
Sony was the sixth-largest manufacturer of CMOS chips last year in shipment volume. Acquiring the Nagasaki plant is said to double the company's image sensor output capacity to the equivalent of about 40,000 silicon wafers a month.
Toshiba will consolidate CMOS sensor production into its Oita Prefecture plant.