Kazuo Iwama, 63, president of the Sony Corp. since 1976, whose rise in the $3 billion worldwide electronics giant was aided by a tiny transistor invented in the United States, died of cancer Aug. 24 in a Tokyo hospital.

Mr. Iwama, who was credited with introducing the world's first transistorized television receiver in 1960, saw the small electronics company rise in the technological boom after World War II as a member of the "triumvirate" that launched the electronics empire.

With his brother-in-law, Akio Morita, considered the prime mover behind Sony, and Masaru Ibuka, Mr. Iwama turned the backyard electrical firm into a company whose products have become a household word around the world.

Mr. Iwama played a key role in working out plans to make Sony the first Japanese company to build a color television manufacturing plant in the United States.

Born in Nagoya, Japan, Mr. Iwama was a graduate of Tokyo University, where he was trained as a geophysical engineer. Morita persuaded him to leave his research job at the university in 1946 and join the newly formed Tokyo Tsushin Kogyo, Sony's predecessor.

The company's breakthrough came in 1954, when Mr. Iwama took the transistor, which had been invented in the United States, and used it to produce Japan's first transistorized radio, the "TR55."

He swiftly climbed the executive ladder at Sony, becoming a director at the age of 31. He was president of Sony's wholly owned U.S. subsidiary, Sony Corp. of America, from 1971 to 1973. He succeeded Morita as president of the parent firm in 1976.

In 1979, Mr. Iwama was honored by Emperor Hirohito, who presented him with a medal for his contributions to the electronics industry. graphics /photo: Kazuo Iwama