Masaru Ibuka, 89, the founder of Sony Corp. who turned a radio repair shop into one of the world's electronics powerhouses, died of congestive heart failure here Dec. 19.

During Mr. Ibuka's tenure, Sony became one of Japan's most successful corporations as the country surged to economic preeminence in the decades after its defeat in World War II.

The company was one of the first Japanese firms to successfully tackle the world markets, and in the process it helped shift the image of Japanese products from junk to excellence.

Mr. Ibuka, who was known as "genius inventor" during his college years, began producing radio parts after he started a repair shop in a bombed-out building in Tokyo in 1945.

Joined by Akio Morita and 20 other people, his factory became a corporation, Tokyo Telecommunications Engineering Corp., which is Sony's former name. Morita, 76, who was Sony's chairman, retired four years ago after suffering a cerebral hemorrhage while playing tennis.

One of Mr. Ibuka's first products was Japan's first tape recorder, "Type-G."

In the early 1950s, Sony bought the rights to a U.S. invention called the transistor and used it in ways its originators never imagined -- in radios. Mr. Ibuka introduced Japan's first transistor radio, "TR-55."

That was the beginning of Sony's reputation for innovation with radios so small they fit in a pocket.

"At that time, research and development of {the} transistor was largely aimed at industrial and military use," Mr. Ibuka said in 1992. "Nobody was thinking about making use of it in commercial products."

The company went on to shrink videotape recorders from huge machines run on vacuum tubes into compact, transistorized models that became a fixture in homes worldwide.

In 1991, Mr. Ibuka wrote a book about his longtime friend Soichiro Honda, who founded Honda Motor Corp.

Survivors include three children.