Why does SH Asset Management oppose Kookmin buyback?

SH Asset Management said it opposes Kookmin Bank, South Korea's biggest lender, buying back five percent of its own shares, becoming the first institutional investor to object to the plan.

SH Asset, a unit banking rival Shinhan Financial Group, said in a regulatory filing it is against Kookmin's move to spend one trillion won ($963 million) on the buyback. The Seoul-based firm didn't say why it opposes the plan.

Kookmin wants to create a holding company, making it easier to use capital for acquisitions. The bank has said it may scrap the restructuring if investors representing more than 15 percent of its stock oppose it.

Kookmin needs approval for its restructuring from two-thirds of the shareholders present, or from holders of one-third of its outstanding shares, during a shareholder meeting on Aug. 25. SH Asset holds 531,600 shares, or 0.16 percent of Kookmin's stock.

The bank plans to purchase 16.84 million shares on the market from Aug. 18 to Nov. 17 to stabilize the stock price, Kookmin said in a regulatory filing Aug. 14.

What could be SH Asset's reasons for resisting the buyback? Will it stick with Kookmin until the lender stabilizes its stock price?