TOKYO (Reuters) -U.S. proxy advisory firm Glass Lewis & Co on Friday recommended shareholders of Japan’s Shinsei Bank Ltd vote for the lender’s plan for a poison pill defence against an unsolicited $1.1 billion bid from SBI Holdings Inc.

Shinsei Bank, a medium-sized bank, opposed SBI last month. It said that it wasn’t known what the suitor would do in order to improve its corporate value. SBI is an online bank and brokerage that holds 20% of Shinsei. It wants to increase this to 48%.

Glass Lewis’s recommendation will likely be seen as an attack on SBI. SBI views Shinsei and its plans to become Japan’s fourth largest bank. Shinsei said that it would consider the offer, provided SBI raises the price or removes the maximum amount it would purchase. However, SBI denied those requests.

Glass Lewis’ recommendation stated that Shinsei’s independent investors were given a partial, inequitable cash out. The restructuring should be followed, Glass Lewis noted.

We believe that this framework is sufficient in rare cases to support Shinsei’s defense measures.

SBI says that it is capable of reorganizing the medium-sized lender and has pledged to return the 350 billion Japanese yen (3.1 billion USD) Shinsei was given during a financial crisis 20 years ago.

Glass Lewis stated that SBI has not offered any investors “a meaningful plan to resolve this problem”.

Shinsei’s shares fell 3% to 1,808 yen on Friday, just below SBI’s offer price at 2,000 yen per share.

($1 = 113.6500 yen)