Sumitomo Electric Industries, Ltd. (SEI) is a manufacturer of electric wire and optical fiber cables. Its headquarters are in Chūō-ku, Osaka, Japan. The company’s shares are listed in the first section of the Tokyo, Nagoya Stock Exchanges, and the Fukuoka Stock Exchange. In the period ending March 2013, the company reported consolidated sales of US$23 billion (2,159,942 million Japanese yen).

The company was founded in 1897 to produce copper wire for electrical uses. Sumitomo operates in five business fields: Automotive, Information & Communications, Electronics, Environment & Energy, and Industrial materials and is developing in two others: Life Sciences and Materials & Resources. It has more than 350 subsidiaries and over 200,000 employees in more than 30 countries.

Sumitomo Electric has traditionally had an intensive focus on R&D to develop new products. Its technologies have been used in major projects including traffic control in Thailand, improvement of telecom networks in Nigeria, membrane technology for wastewater treatment in Korea, and bridge construction in Germany.

Sumitomo Electric’s electrical wiring harness systems, which are used to send information and energy to automobiles, hold the second largest market share in the world. Sumitomo Electric also continues to be the leading manufacturer of composite semiconductors (GaAs, GaN, InP), which are widely used in semiconductor lasers, LEDs, and mobile telecommunications devices. The company is one of the top three manufacturers in the world of optical fiber.