Japanese mobile firm SoftBank said Wednesday its nine-month net profit doubled, largely due to one-off gains from the sale of its stake in Chinese e-commerce giant Alibaba.

The company said April-December net profit came in at 857.4 billion yen ($7.6 billion), up 99.9 percent from the previous year, while operating profit rose 18 percent from a year ago.

Apart from the Alibaba sale, SoftBank pointed to improvements at its money-losing US subsidiary Sprint as well as the acquisition of iPhone chip designer ARM Holdings.

Revenue edged down 0.3 percent to 6.58 trillion yen, the company added, citing the impact of a stronger yen.

The firm did not release earnings estimates for its fiscal year to March.

SoftBank reaped huge profits from a partial sale of its stake in Alibaba, China'a equivalent to eBay, while in June it sold Finnish game-maker Supercell Oy, creator of "Clash of Clans", to Chinese internet behemoth Tencent for $8.6 billion.

Also last year, SoftBank announced the $32-billion ARM purchase.

Led by flamboyant founder Masayoshi Son, SoftBank has embarked on a string of international acquisitions both big and small in recent years.

Son was among the first business people to meet with Donald Trump after his November election victory.

Son pledged to invest $50 billion in business and job-creation in the United States, winning open praise from the then president-elect.