In a report from Institutional Shareholder Services, it had urged investors in Sprint-Nextel Corp to accept the Softbank Corp bid worth US$20.1 billion. The deal would allow Spring to expand in the US mobile phone market, according to the advisory form as reported by Bloomberg News.

The ISS assessment says that the Softbank offer would give Sprint more capital to acquire more spectrum and improve its existing network. 

The date for the said shareholder vote is June 12. The Softbank takeover bid is being challenged by a counterbid by Dish Network Corp, whose bid is worth US$25.5 billion. Sprint is the third largest US mobile phone carrier and it is seeking a partner to compete against market leaders AT&T Inc and Verizon Wireless.

When sought for comment, Cheryl Gustitus, spokeswoman for ISS, did not immediately respond to a request made after office hours. On the other hand, spokesman for Sprint, Scott Sloat and spokesman for Dish, Bob Toevs, both did not respond to messages sent for comment after office hours. Calls made to the Tokyo office of Softbank went unanswered after office hours.

The Rockvill, MD based advisory firm's statement comes after Egan-Jones Ratings Co had recommended that Sprint investors refuse Softbank's takeover bid.