Elliott has built up a roughly 3% stake in the tech conglomerate and is pushing for changes to boost its value including strengthening corporate governance and share buybacks, sources said.
Elliott "thinks the company valuation is too low so in that sense it is currently a positive for SoftBank Group," Miyauchi said, adding he believed corporate governance at the telco he heads was already strong.
SoftBank Group's shares, which company executives think are chronically undervalued, closed up 7% on Friday after reports of the Elliott investment.
The comments came as SoftBank Corp reported a 15% rise in third-quarter operating profit, beating estimates, underpinned by its mobile business.
The company also raised its full-year operating profit forecast to 900 billion yen ($8.2 billion) from 890 billion yen previously.
Operating profit in the October-December quarter was 243 billion yen versus 211 billion yen a year earlier. That compared with an average forecast of 240 billion yen from three analyst estimates compiled by Refinitiv.
Japan's third-largest telecom, SoftBank Corp has pledged to pay out 85% of its net income as dividends, providing a steady stream of cash to parent SoftBank Group, which holds a 67% stake. As such, SoftBank Corp has become a popular stock for yield-hungry Japanese retail investors.
Miyauchi said dividends, rather than share buybacks, are the priority.
Along with a 26% stake in China's Alibaba, the wireless carrier continues to help to support the market value of its parent, which in the quarter ended September reported its first quarterly loss in 14 years as its tech bets faltered.
Founder Masayoshi Son built his fortune by breaking into Japan's telecoms market but his reputation could be determined by the performance of the $100 billion Vision Fund, which will report at the group's results on Wednesday.
SoftBank Corp rivals NTT Docomo and KDDI Corp reported last week that operating profit fell 15% and rose 11%, respectively.
SoftBank's stable earnings contrast with the fortunes of one of Son's big early overseas bets, U.S wireless unit Sprint Corp, which last week reported falling subscriber numbers.
Analysts said prospects for the money-losing company are grim if it does not reach a merger with larger rival T-Mobile US Inc.
Japan's three incumbent telecoms are holding their breath for the announcement of pricing plans from Rakuten Inc, which will launch wireless services in April and is expected to offer aggressively low prices.
SoftBank Corp's shares closed up around 1% ahead of the earnings release.
By Sam Nussey
