Dalton Investments, a $3.4 billion U.S. investment firm, says it¡¯s still on the fence over whether to support Shinsei Bank Ltd.¡¯s management or SBI Holdings Inc. in the battle for control of the Japanese lender.

Neither side has given a convincing argument for its backing, said Jamie Rosenwald, a Dalton co-founder and portfolio manager.

Shinsei should have found an alternative buyer willing to pay more, while SBI should bid for the entire company rather than just a partial stake, he said.