Sumitomo's Executive Vice President Ueno, 64, has played a pivotal role in leading the metals, resources and chemicals businesses, while overseeing the development of next-generation energy projects, including hydrogen initiatives.
Amid the global shift towards a low-carbon economy, Sumitomo aims to fortify its presence in growth areas, Ueno said.
"I aspire to drive the company's evolution by implementing comprehensive reforms," Ueno told a news conference.
Sumitomo is one of Japan's top trading companies, in which U.S. billionaire investor Warren Buffett has a stake.
(Reporting by Yuka Obayashi; Editing by Alexander Smith)