HONG KONG—A top executive of Japan’s SoftBank Group Corp. said the company is still committed to turning around Sprint Corp., the struggling U.S. wireless carrier it owns, though it takes a long time for the telecom industry to change.

“Telecom business is a long-term business...It takes a while to shift the direction in the industry,” said SoftBank President Nikesh Arora at the Converge technology conference in Hong Kong on Thursday.

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