Warren Buffett’s Berkshire Hathaway Inc. sold yen bonds at lower costs in its second Japan deal of the year as speculation mounts that the billionaire investor may put more money into the nation’s share market.

In a ¥122 billion ($810 million) offering of five tenors of notes ranging from three years to 35 years, the firm was able to reduce spreads compared with its previous sale. It priced three-year bonds at a premium of 59 basis points over swaps versus 75 basis points in April, at a time of heightened market volatility after the appointment of Kazuo Ueda as Bank of Japan governor and banking-sector troubles overseas.