Investors are waiting for SoftBank Corp. to revise its global growth strategy after Chief Executive Officer Masayoshi Son's plan to challenge the two leaders in the U.S. market took a hit when its bid to acquire T-Mobile U.S. Inc. via new subsidiary Sprint Corp. was apparently foiled by American antitrust concerns.

Analysts said market players are closely watching to see how SoftBank will shore up the business of the third-largest U.S. mobile carrier, acquired in July last year for $21.6 billion, without the No. 4 player.

Others said SoftBank dropped out of the bidding because it might be considering better options to expand through mergers and acquisitions outside the field of telecommunications.