Japan's SoftBank Group said on Wednesday its net profit jumped more than 50 percent for the nine months to December thanks to strong returns from its high-tech investment fund.

Net profit rose 51.6 percent from a year earlier to 1.5 trillion yen ($13.7 billion), the mobile giant and IT investor said.

The rise was largely driven by gains of more than 800 billion yen from its investment funds, led by SoftBank Vision Fund whose partners include Saudi Arabia.

SoftBank Corp, the mobile carrier arm of the technology conglomerate, said Tuesday its net profit jumped nearly 19 percent for the nine months to December, buoyed by a gain in subscribers.

It was the first earnings announcement since its disappointing stock market debut in December.

Under tycoon CEO Masayoshi Son, SoftBank, which started as a software firm, has increasingly been seen as an investment firm, ploughing funds into a broad range of companies and projects outside its core business.

In recent years, it has completed deals with the likes of French robotics firm Aldebaran and Chinese e-commerce giant Alibaba.

It has also made high-profile investments in the autonomous vehicles sector, announcing a tie-up with car giant Toyota for "new mobility services" such as meal deliveries.