Profits doubled in the third quarter at SoftBank Corp., the Tokyo-based company that is buying 70 percent of Sprint Nextel Corp., as Japan’s No. 3 wireless carrier lured new customers with Apple Inc. smartphones and tablet computers.

Its stronger report comes a week ahead of Sprint’s year-end financial report, which is scheduled for release Feb. 7.

SoftBank said its net income rose to 65.9 billion yen, or $724 million, in the three months that ended Dec. 31 from 32.8 billion yen a year earlier. Sales gained 7.1 percent to 923.7 billion yen.

“Everything’s going well for Softbank, unlike DoCoMo,” said Hitoshi Hayakawa, an analyst at Credit Suisse Group AG. NTT DoCoMo Inc. is Japan’s largest wireless carrier.

DoCoMo’s operating profit for the nine months ended Dec. 31 fell 5.6 percent from a year earlier.

Sprint and SoftBank agreed in October to the $20.1 billion deal that has yet to be presented to Sprint shareholders for a vote. Sprint also has an agreement to acquire the roughly 49 percent of Clearwire Corp. that it doesn’t already own.

SoftBank said it would cooperate with regulators’ review of its Sprint deal. The U.S. Department of Justice has asked the Federal Communications Commission to delay the review because of SoftBank’s ties to Chinese suppliers of telecommunications equipment.

SoftBank founder Masayoshi Son said in October he expected the deal to be scrutinized on national-security grounds.