The Japanese government converted NTT from a fully state-owned public corporation into a private company, part of a wave of deregulation that also opened the market to new competitors like DDI. The move reshaped Japan's telecom and, later, internet infrastructure landscape.
For over three decades, Nippon Telegraph and Telephone Public Corporation held an absolute monopoly over Japan's domestic phone network, a state-run utility with little incentive for innovation or cost-cutting. As Japan's economy boomed through the 1970s and 80s, pressure mounted from business leaders and Western trade partners to break open the sector.
On January 11, 1985, NTT was formally reorganized as a private, though initially government-majority-owned, joint-stock company, following legislation passed the previous year. Simultaneously, Japan's telecom market opened to competitors for the first time, most notably Daini Denden (later KDDI), founded by entrepreneur Kazuo Inamori.
The privatization proved wildly lucrative when NTT shares finally floated on the Tokyo Stock Exchange in 1987, reaching valuations so high that NTT was briefly worth more than the entire West German stock market. The deregulated environment that followed laid groundwork for Japan's rapid buildout of digital and later mobile internet infrastructure in the 1990s and 2000s.