SoftBank Corp. unveiled on Monday a new smartphone developed with U.S. subsidiary Sprint Corp. to cut procurement costs and strengthen its product lineup.

Manufactured by Sharp Corp., the first handset developed with the third-largest U.S. mobile phone carrier goes on sale in Japan on Aug. 29 and is expected to hit the U.S. market soon, according to SoftBank.

With a 5-inch display, the Aquos Crystal boasts a thin frame and comes with a high-quality wireless speaker, according to the telecom company.

"With the expansion of a procurement scale, we can provide competitive devices with our own specification," said Maki Tahara, head of marketing strategy at SoftBank Mobile Corp., the firm's mobile phone services provider, at a news conference in Tokyo.